diff --git a/include/cpp2util.h b/include/cpp2util.h
index cffd93ac9..73124e563 100644
--- a/include/cpp2util.h
+++ b/include/cpp2util.h
@@ -356,6 +356,125 @@ using longdouble = long double;
 using _schar     = signed char;      // normally use i8 instead
 using _uchar     = unsigned char;    // normally use u8 instead
 
+//-----------------------------------------------------------------------
+//
+//  Helper for concepts
+//
+//-----------------------------------------------------------------------
+//
+
+template<typename Ret, typename Arg>
+auto argument_of_helper(Ret(*) (Arg)) -> Arg;
+
+template<typename Ret, typename F, typename Arg>
+auto argument_of_helper(Ret(F::*) (Arg)) -> Arg;
+
+template<typename Ret, typename F, typename Arg>
+auto argument_of_helper(Ret(F::*) (Arg)&) -> Arg;
+
+template<typename Ret, typename F, typename Arg>
+auto argument_of_helper(Ret(F::*) (Arg)&&) -> Arg;
+
+template<typename Ret, typename F, typename Arg>
+auto argument_of_helper(Ret(F::*) (Arg) const) -> Arg;
+
+template<typename Ret, typename F, typename Arg>
+auto argument_of_helper(Ret(F::*) (Arg) const&) -> Arg;
+
+template<typename Ret, typename F, typename Arg>
+auto argument_of_helper(Ret(F::*) (Arg) const&&) -> Arg;
+
+template <typename F>
+auto argument_of_helper(F const&) -> CPP2_TYPEOF(argument_of_helper(&F::operator()));
+
+template <typename T>
+using argument_of_t = CPP2_TYPEOF(argument_of_helper(std::declval<T>()));
+
+template <typename F>
+auto argument_of_helper_op_is(F const&) -> CPP2_TYPEOF(argument_of_helper(&F::op_is));
+
+template <typename T>
+using argument_of_op_is_t = CPP2_TYPEOF(argument_of_helper_op_is(std::declval<T>()));
+
+template <typename T>
+using pointee_t = std::iter_value_t<T>;
+
+template <template <typename...> class C, typename... Ts>
+constexpr auto specialization_of_template_helper(C< Ts...> const& ) -> std::true_type {
+    return {};
+}
+
+template <template <typename, auto...> class C, typename T, auto... Ns>
+    requires (sizeof...(Ns) > 0)
+constexpr auto specialization_of_template_helper(C< T, Ns... > const& ) -> std::true_type {
+    return {};
+}
+
+//-----------------------------------------------------------------------
+//
+//  Concepts
+//
+//-----------------------------------------------------------------------
+//
+
+template <typename X, template<typename...> class C>
+concept specialization_of_template = requires (X x) {
+    { specialization_of_template_helper<C>(std::forward<X>(x)) } -> std::same_as<std::true_type>;
+};
+
+template <typename X, template<typename,auto...> class C>
+concept specialization_of_template_type_and_nttp = requires (X x) {
+    { specialization_of_template_helper<C>(std::forward<X>(x)) } -> std::same_as<std::true_type>;
+};
+
+template <typename X>
+concept dereferencable = requires (X x) { *x; };
+
+template <typename X>
+concept default_constructible = std::is_default_constructible_v<std::remove_cvref_t<X>>;
+
+template <typename X>
+concept bounded_array = std::is_bounded_array_v<std::remove_cvref_t<X>>;
+
+template <typename X>
+concept pointer_like = dereferencable<X> && default_constructible<X> && std::equality_comparable<X>
+                       && !bounded_array<X>;
+
+template< typename From, typename To >
+concept brace_initializable_to = requires (From x) { To{x}; };
+
+template< typename X, typename C >
+concept same_type_as = std::same_as<std::remove_cvref_t<X>, std::remove_cvref_t<C>>;
+
+template <typename X>
+concept defined = requires { std::declval<X>(); };
+
+template <typename X>
+concept has_defined_argument = requires {
+	std::declval<argument_of_t<X>>();
+};
+
+template <typename X, typename F>
+concept covertible_to_argument_of = same_type_as<X,argument_of_t<F>>
+                                 || (pointer_like<argument_of_t<F>> && brace_initializable_to<X, pointee_t<argument_of_t<F>>>)
+                                 || (!pointer_like<argument_of_t<F>> && brace_initializable_to<X, argument_of_t<F>>)
+                                 ;
+
+template <typename F, typename X>
+concept valid_predicate = (std::predicate<F, X> && !has_defined_argument<F>)
+                          || (std::predicate<F, X> && has_defined_argument<F> && covertible_to_argument_of<X, F>);
+
+template <typename X, typename O, auto mem_fun_ptr>
+concept predicate_member_fun = requires (X x, O o) {
+    { (o.*mem_fun_ptr)(x) } -> std::convertible_to<bool>;
+};
+
+template <typename F, typename X>
+concept valid_custom_is_operator = predicate_member_fun<X, F, &F::op_is>
+                      && ( 
+                        !defined<argument_of_op_is_t<F>>
+                        || brace_initializable_to<X, argument_of_op_is_t<F>> 
+                      );
 
 //-----------------------------------------------------------------------
 //
@@ -1116,7 +1235,7 @@ inline auto to_string(std::tuple<Ts...> const& t) -> std::string
 #if defined(__cpp_lib_format) || (defined(_MSC_VER) && _MSC_VER >= 1929)
 inline auto to_string(auto&& value, std::string_view fmt) -> std::string
 {
-    return std::vformat(fmt, std::make_format_args(CPP2_FORWARD(value)));
+    return std::vformat(fmt, std::make_format_args(value));
 }
 #else
 inline auto to_string(auto&& value, std::string_view) -> std::string
@@ -1149,31 +1268,24 @@ using empty = void;
 
 //  Templates
 //
-template <template <typename...> class C, typename... Ts>
-constexpr auto is(C< Ts...> const& ) -> bool {
-    return true;
-}
-
-#if defined(_MSC_VER)
-    template <template <typename, typename...> class C, typename T>
-    constexpr auto is( T const& ) -> bool {
-        return false;
+template <template <typename...> class C, typename X>
+constexpr auto is( X&& ) {
+    if constexpr (specialization_of_template<X, C>) {
+        return std::true_type{};
     }
-#else
-    template <template <typename...> class C, typename T>
-    constexpr auto is( T const& ) -> bool {
-        return false;
+    else {
+        return std::false_type{};
     }
-#endif
-
-template <template <typename,auto> class C, typename T, auto V>
-constexpr auto is( C<T, V> const& ) -> bool {
-    return true;
 }
 
-template <template <typename,auto> class C, typename T>
-constexpr auto is( T const& ) -> bool {
-    return false;
+template <template <typename, auto> class C, typename X>
+constexpr auto is( X&& ) {
+    if constexpr (specialization_of_template_type_and_nttp<X, C>) {
+        return std::true_type{};
+    }
+    else {
+        return std::false_type{};
+    }
 }
 
 //  Types
@@ -1220,25 +1332,37 @@ auto is( X const& x ) -> bool {
 inline constexpr auto is( auto const& x, auto&& value ) -> bool
 {
     //  Value with customized operator_is case
-    if constexpr (requires{ x.op_is(value); }) {
+    if constexpr (valid_custom_is_operator<decltype(x), decltype(value)>) {
         return x.op_is(value);
     }
 
     //  Predicate case
-    else if constexpr (requires{ bool{ value(x) }; }) {
+    else if constexpr (valid_predicate<decltype(value), decltype(x)>) {
         return value(x);
     }
-    else if constexpr (std::is_function_v<decltype(value)> || requires{ &value.operator(); }) {
+
+    //  Value equality case: C/C++ arrays or individual values
+    else if constexpr (std::is_array_v<CPP2_TYPEOF(x)> && std::is_array_v<CPP2_TYPEOF(value)>) {
+        if (std::ssize(x) == std::ssize(value)) {
+            return std::equal( std::begin(x), std::end(x), std::begin(value));
+        }
         return false;
     }
-
-    //  Value equality case
     else if constexpr (requires{ bool{x == value}; }) {
         return x == value;
     }
     return false;
 }
 
+//-----------------------------------------------------------------------
+//
+//  and "is predicate" for generic function used as predicate
+//
+
+template <typename X>
+inline constexpr auto is( X const& x, bool (*value)(X const&) ) -> bool {
+    return value(x);
+}
 
 //-------------------------------------------------------------------------------------------------------------
 //  Built-in as
diff --git a/regression-tests/pure2-is-with-free-functions-predicate.cpp2 b/regression-tests/pure2-is-with-free-functions-predicate.cpp2
new file mode 100644
index 000000000..b2e0f145c
--- /dev/null
+++ b/regression-tests/pure2-is-with-free-functions-predicate.cpp2
@@ -0,0 +1,31 @@
+fun: (v) = {
+    if v is (pred_i) {
+        std::cout << "(v)$ is integer bigger than 3" << std::endl;
+    }
+
+    if v is (pred_d) {
+        std::cout << "(v)$ is double bigger than 3" << std::endl;
+    }
+
+    if v is (pred_) {
+        std::cout << "(v)$ is bigger than 3" << std::endl;
+    }
+}
+
+main: () -> int = {
+    fun(3.14);
+    fun(42);
+    fun('a');
+}
+
+pred_i: (x : int ) -> bool = {
+    return x > 3;
+}
+
+pred_d: (x : double ) -> bool = {
+    return x > 3;
+}
+
+pred_: (x) -> bool = {
+    return x > 3;
+}
diff --git a/regression-tests/pure2-is-with-unnamed-predicates.cpp2 b/regression-tests/pure2-is-with-unnamed-predicates.cpp2
new file mode 100644
index 000000000..d7253551e
--- /dev/null
+++ b/regression-tests/pure2-is-with-unnamed-predicates.cpp2
@@ -0,0 +1,19 @@
+fun: (v) = {
+    if v is (:(x:int) x>3;) {
+        std::cout << "(v)$ is integer bigger than 3" << std::endl;
+    }
+
+    if v is (:(x:double) x>3;) {
+        std::cout << "(v)$ is double bigger than 3" << std::endl;
+    }
+
+    if v is (:(x) x>3;) {
+        std::cout << "(v)$ is bigger than 3" << std::endl;
+    }
+}
+
+main: () -> int = {
+    fun(3.14);
+    fun(42);
+    fun('a');
+}
diff --git a/regression-tests/pure2-is-with-variable-and-value.cpp2 b/regression-tests/pure2-is-with-variable-and-value.cpp2
new file mode 100644
index 000000000..c207cc2c2
--- /dev/null
+++ b/regression-tests/pure2-is-with-variable-and-value.cpp2
@@ -0,0 +1,41 @@
+fun: (name, v) = {
+    std::cout << name << ": " <<
+                inspect v -> std::string {
+                is (42) = "42";
+                is (123) = "op_is";
+                is (-123) = "generic op_is";
+                is (4321) = "comparable";
+                is ("text") = "text";
+                is _ = "unknown";
+              }
+              << std::endl;
+}
+
+main: () -> int = {
+    fun("3.14", 3.14);
+    fun("42", 42);
+    fun("WithOp()", WithOp());
+    fun("WithGenOp()", WithGenOp());
+    fun("Cmp()", Cmp());
+    fun("std::string(\"text\")", std::string("text"));
+    fun("\"text\"", "text");
+    fun("std::string_view(\"text\")", std::string_view("text"));
+    fun(":std::vector = ('t','e','x','t','\\0')", :std::vector = ('t','e','x','t','\0'));
+}
+
+WithOp : type = {
+    op_is: (this, x : int) x == 123;
+}
+
+WithGenOp : type = {
+    op_is: (this, x) -> bool = {
+        if constexpr std::convertible_to<decltype(x), int> {
+            return x == -123;
+        }
+        return false;
+    }
+}
+
+Cmp : type = {
+    operator==: (this, x : int) -> bool = x == 4321;
+}
diff --git a/regression-tests/test-results/apple-clang-14/mixed-inspect-values.cpp.execution b/regression-tests/test-results/apple-clang-14/mixed-inspect-values.cpp.execution
index 245368cfc..e7130e0f8 100644
--- a/regression-tests/test-results/apple-clang-14/mixed-inspect-values.cpp.execution
+++ b/regression-tests/test-results/apple-clang-14/mixed-inspect-values.cpp.execution
@@ -9,4 +9,4 @@ zero
 3
 integer -42
 xyzzy
-3
+(no match)
diff --git a/regression-tests/test-results/apple-clang-14/pure2-is-with-free-functions-predicate.cpp.execution b/regression-tests/test-results/apple-clang-14/pure2-is-with-free-functions-predicate.cpp.execution
new file mode 100644
index 000000000..c8a07e430
--- /dev/null
+++ b/regression-tests/test-results/apple-clang-14/pure2-is-with-free-functions-predicate.cpp.execution
@@ -0,0 +1,6 @@
+3.140000 is double bigger than 3
+3.140000 is bigger than 3
+42 is integer bigger than 3
+42 is bigger than 3
+a is integer bigger than 3
+a is bigger than 3
diff --git a/regression-tests/test-results/apple-clang-14/pure2-is-with-free-functions-predicate.cpp.output b/regression-tests/test-results/apple-clang-14/pure2-is-with-free-functions-predicate.cpp.output
new file mode 100644
index 000000000..e69de29bb
diff --git a/regression-tests/test-results/apple-clang-14/pure2-is-with-unnamed-predicates.cpp.execution b/regression-tests/test-results/apple-clang-14/pure2-is-with-unnamed-predicates.cpp.execution
new file mode 100644
index 000000000..c8a07e430
--- /dev/null
+++ b/regression-tests/test-results/apple-clang-14/pure2-is-with-unnamed-predicates.cpp.execution
@@ -0,0 +1,6 @@
+3.140000 is double bigger than 3
+3.140000 is bigger than 3
+42 is integer bigger than 3
+42 is bigger than 3
+a is integer bigger than 3
+a is bigger than 3
diff --git a/regression-tests/test-results/apple-clang-14/pure2-is-with-unnamed-predicates.cpp.output b/regression-tests/test-results/apple-clang-14/pure2-is-with-unnamed-predicates.cpp.output
new file mode 100644
index 000000000..e69de29bb
diff --git a/regression-tests/test-results/apple-clang-14/pure2-is-with-variable-and-value.cpp.execution b/regression-tests/test-results/apple-clang-14/pure2-is-with-variable-and-value.cpp.execution
new file mode 100644
index 000000000..0b4a1cdf5
--- /dev/null
+++ b/regression-tests/test-results/apple-clang-14/pure2-is-with-variable-and-value.cpp.execution
@@ -0,0 +1,9 @@
+3.14: unknown
+42: 42
+WithOp(): unknown
+WithGenOp(): unknown
+Cmp(): comperable
+std::string("text"): text
+"text": text
+std::string_view("text"): text
+:std::vector = ('t','e','x','t','\0'): unknown
diff --git a/regression-tests/test-results/apple-clang-14/pure2-is-with-variable-and-value.cpp.output b/regression-tests/test-results/apple-clang-14/pure2-is-with-variable-and-value.cpp.output
new file mode 100644
index 000000000..e69de29bb
diff --git a/regression-tests/test-results/clang-12/mixed-bugfix-for-ufcs-non-local.cpp.output b/regression-tests/test-results/clang-12/mixed-bugfix-for-ufcs-non-local.cpp.output
index 13c5abdbc..8db1cd1f2 100644
--- a/regression-tests/test-results/clang-12/mixed-bugfix-for-ufcs-non-local.cpp.output
+++ b/regression-tests/test-results/clang-12/mixed-bugfix-for-ufcs-non-local.cpp.output
@@ -1,118 +1,118 @@
 mixed-bugfix-for-ufcs-non-local.cpp2:13:12: error: a lambda expression cannot appear in this context
 template<t<CPP2_UFCS_NONLOCAL(f)(o)> UnnamedTypeParam1_1> bool inline constexpr v0 = false;// Fails on GCC ([GCC109781][]) and Clang 12 (a lambda expression cannot appear in this context)
            ^
-../../../include/cpp2util.h:993:59: note: expanded from macro 'CPP2_UFCS_NONLOCAL'
+../../../include/cpp2util.h:1112:59: note: expanded from macro 'CPP2_UFCS_NONLOCAL'
 #define CPP2_UFCS_NONLOCAL(...)                           CPP2_UFCS_(,CPP2_UFCS_IDENTITY,CPP2_UFCS_IDENTITY,(),,__VA_ARGS__)
                                                           ^
-../../../include/cpp2util.h:955:66: note: expanded from macro 'CPP2_UFCS_'
+../../../include/cpp2util.h:1074:66: note: expanded from macro 'CPP2_UFCS_'
 #define CPP2_UFCS_(LAMBDADEFCAPT,SFINAE,MVFWD,QUALID,TEMPKW,...) \
                                                                  ^
 mixed-bugfix-for-ufcs-non-local.cpp2:15:3: error: a lambda expression cannot appear in this context
 t<CPP2_UFCS_NONLOCAL(f)(o)> inline constexpr v1 = t<true>();// Fails on Clang 12 (lambda in unevaluated context).
   ^
-../../../include/cpp2util.h:993:59: note: expanded from macro 'CPP2_UFCS_NONLOCAL'
+../../../include/cpp2util.h:1112:59: note: expanded from macro 'CPP2_UFCS_NONLOCAL'
 #define CPP2_UFCS_NONLOCAL(...)                           CPP2_UFCS_(,CPP2_UFCS_IDENTITY,CPP2_UFCS_IDENTITY,(),,__VA_ARGS__)
                                                           ^
-../../../include/cpp2util.h:955:66: note: expanded from macro 'CPP2_UFCS_'
+../../../include/cpp2util.h:1074:66: note: expanded from macro 'CPP2_UFCS_'
 #define CPP2_UFCS_(LAMBDADEFCAPT,SFINAE,MVFWD,QUALID,TEMPKW,...) \
                                                                  ^
 mixed-bugfix-for-ufcs-non-local.cpp2:21:12: error: a lambda expression cannot appear in this context
 template<t<CPP2_UFCS_NONLOCAL(f)(o)> UnnamedTypeParam1_2> auto g() -> void;
            ^
-../../../include/cpp2util.h:993:59: note: expanded from macro 'CPP2_UFCS_NONLOCAL'
+../../../include/cpp2util.h:1112:59: note: expanded from macro 'CPP2_UFCS_NONLOCAL'
 #define CPP2_UFCS_NONLOCAL(...)                           CPP2_UFCS_(,CPP2_UFCS_IDENTITY,CPP2_UFCS_IDENTITY,(),,__VA_ARGS__)
                                                           ^
-../../../include/cpp2util.h:955:66: note: expanded from macro 'CPP2_UFCS_'
+../../../include/cpp2util.h:1074:66: note: expanded from macro 'CPP2_UFCS_'
 #define CPP2_UFCS_(LAMBDADEFCAPT,SFINAE,MVFWD,QUALID,TEMPKW,...) \
                                                                  ^
 mixed-bugfix-for-ufcs-non-local.cpp2:23:42: error: a lambda expression cannot appear in this context
 auto g([[maybe_unused]] cpp2::impl::in<t<CPP2_UFCS_NONLOCAL(f)(o)>> unnamed_param_1) -> void;
                                          ^
-../../../include/cpp2util.h:993:59: note: expanded from macro 'CPP2_UFCS_NONLOCAL'
+../../../include/cpp2util.h:1112:59: note: expanded from macro 'CPP2_UFCS_NONLOCAL'
 #define CPP2_UFCS_NONLOCAL(...)                           CPP2_UFCS_(,CPP2_UFCS_IDENTITY,CPP2_UFCS_IDENTITY,(),,__VA_ARGS__)
                                                           ^
-../../../include/cpp2util.h:955:66: note: expanded from macro 'CPP2_UFCS_'
+../../../include/cpp2util.h:1074:66: note: expanded from macro 'CPP2_UFCS_'
 #define CPP2_UFCS_(LAMBDADEFCAPT,SFINAE,MVFWD,QUALID,TEMPKW,...) \
                                                                  ^
 mixed-bugfix-for-ufcs-non-local.cpp2:27:29: error: a lambda expression cannot appear in this context
 [[nodiscard]] auto h() -> t<CPP2_UFCS_NONLOCAL(f)(o)>;
                             ^
-../../../include/cpp2util.h:993:59: note: expanded from macro 'CPP2_UFCS_NONLOCAL'
+../../../include/cpp2util.h:1112:59: note: expanded from macro 'CPP2_UFCS_NONLOCAL'
 #define CPP2_UFCS_NONLOCAL(...)                           CPP2_UFCS_(,CPP2_UFCS_IDENTITY,CPP2_UFCS_IDENTITY,(),,__VA_ARGS__)
                                                           ^
-../../../include/cpp2util.h:955:66: note: expanded from macro 'CPP2_UFCS_'
+../../../include/cpp2util.h:1074:66: note: expanded from macro 'CPP2_UFCS_'
 #define CPP2_UFCS_(LAMBDADEFCAPT,SFINAE,MVFWD,QUALID,TEMPKW,...) \
                                                                  ^
 mixed-bugfix-for-ufcs-non-local.cpp2:31:12: error: a lambda expression cannot appear in this context
 template<t<CPP2_UFCS_NONLOCAL(f)(o)> UnnamedTypeParam1_3> using a = bool;// Fails on GCC ([GCC109781][]) and Clang 12 (a lambda expression cannot appear in this context)
            ^
-../../../include/cpp2util.h:993:59: note: expanded from macro 'CPP2_UFCS_NONLOCAL'
+../../../include/cpp2util.h:1112:59: note: expanded from macro 'CPP2_UFCS_NONLOCAL'
 #define CPP2_UFCS_NONLOCAL(...)                           CPP2_UFCS_(,CPP2_UFCS_IDENTITY,CPP2_UFCS_IDENTITY,(),,__VA_ARGS__)
                                                           ^
-../../../include/cpp2util.h:955:66: note: expanded from macro 'CPP2_UFCS_'
+../../../include/cpp2util.h:1074:66: note: expanded from macro 'CPP2_UFCS_'
 #define CPP2_UFCS_(LAMBDADEFCAPT,SFINAE,MVFWD,QUALID,TEMPKW,...) \
                                                                  ^
 mixed-bugfix-for-ufcs-non-local.cpp2:33:12: error: a lambda expression cannot appear in this context
 template<t<CPP2_UFCS_NONLOCAL(f)(o)> UnnamedTypeParam1_4> auto inline constexpr b = false;// Fails on GCC ([GCC109781][]).
            ^
-../../../include/cpp2util.h:993:59: note: expanded from macro 'CPP2_UFCS_NONLOCAL'
+../../../include/cpp2util.h:1112:59: note: expanded from macro 'CPP2_UFCS_NONLOCAL'
 #define CPP2_UFCS_NONLOCAL(...)                           CPP2_UFCS_(,CPP2_UFCS_IDENTITY,CPP2_UFCS_IDENTITY,(),,__VA_ARGS__)
                                                           ^
-../../../include/cpp2util.h:955:66: note: expanded from macro 'CPP2_UFCS_'
+../../../include/cpp2util.h:1074:66: note: expanded from macro 'CPP2_UFCS_'
 #define CPP2_UFCS_(LAMBDADEFCAPT,SFINAE,MVFWD,QUALID,TEMPKW,...) \
                                                                  ^
 mixed-bugfix-for-ufcs-non-local.cpp2:35:13: error: a lambda expression cannot appear in this context
 using c = t<CPP2_UFCS_NONLOCAL(f)(o)>;// Fails on Clang 12 (lambda in unevaluated context) and Clang 12 (a lambda expression cannot appear in this context)
             ^
-../../../include/cpp2util.h:993:59: note: expanded from macro 'CPP2_UFCS_NONLOCAL'
+../../../include/cpp2util.h:1112:59: note: expanded from macro 'CPP2_UFCS_NONLOCAL'
 #define CPP2_UFCS_NONLOCAL(...)                           CPP2_UFCS_(,CPP2_UFCS_IDENTITY,CPP2_UFCS_IDENTITY,(),,__VA_ARGS__)
                                                           ^
-../../../include/cpp2util.h:955:66: note: expanded from macro 'CPP2_UFCS_'
+../../../include/cpp2util.h:1074:66: note: expanded from macro 'CPP2_UFCS_'
 #define CPP2_UFCS_(LAMBDADEFCAPT,SFINAE,MVFWD,QUALID,TEMPKW,...) \
                                                                  ^
 mixed-bugfix-for-ufcs-non-local.cpp2:37:29: error: a lambda expression cannot appear in this context
 auto inline constexpr d = t<CPP2_UFCS_NONLOCAL(f)(o)>();// Fails on Clang 12 (lambda in unevaluated context).
                             ^
-../../../include/cpp2util.h:993:59: note: expanded from macro 'CPP2_UFCS_NONLOCAL'
+../../../include/cpp2util.h:1112:59: note: expanded from macro 'CPP2_UFCS_NONLOCAL'
 #define CPP2_UFCS_NONLOCAL(...)                           CPP2_UFCS_(,CPP2_UFCS_IDENTITY,CPP2_UFCS_IDENTITY,(),,__VA_ARGS__)
                                                           ^
-../../../include/cpp2util.h:955:66: note: expanded from macro 'CPP2_UFCS_'
+../../../include/cpp2util.h:1074:66: note: expanded from macro 'CPP2_UFCS_'
 #define CPP2_UFCS_(LAMBDADEFCAPT,SFINAE,MVFWD,QUALID,TEMPKW,...) \
                                                                  ^
 mixed-bugfix-for-ufcs-non-local.cpp2:21:12: error: a lambda expression cannot appear in this context
 template<t<CPP2_UFCS_NONLOCAL(f)(o)> UnnamedTypeParam1_2> auto g() -> void{}// Fails on GCC ([GCC109781][]) and Clang 12 (a lambda expression cannot appear in this context)
            ^
-../../../include/cpp2util.h:993:59: note: expanded from macro 'CPP2_UFCS_NONLOCAL'
+../../../include/cpp2util.h:1112:59: note: expanded from macro 'CPP2_UFCS_NONLOCAL'
 #define CPP2_UFCS_NONLOCAL(...)                           CPP2_UFCS_(,CPP2_UFCS_IDENTITY,CPP2_UFCS_IDENTITY,(),,__VA_ARGS__)
                                                           ^
-../../../include/cpp2util.h:955:66: note: expanded from macro 'CPP2_UFCS_'
+../../../include/cpp2util.h:1074:66: note: expanded from macro 'CPP2_UFCS_'
 #define CPP2_UFCS_(LAMBDADEFCAPT,SFINAE,MVFWD,QUALID,TEMPKW,...) \
                                                                  ^
 mixed-bugfix-for-ufcs-non-local.cpp2:23:42: error: a lambda expression cannot appear in this context
 auto g([[maybe_unused]] cpp2::impl::in<t<CPP2_UFCS_NONLOCAL(f)(o)>> unnamed_param_1) -> void{}// Fails on Clang 12 (lambda in unevaluated context).
                                          ^
-../../../include/cpp2util.h:993:59: note: expanded from macro 'CPP2_UFCS_NONLOCAL'
+../../../include/cpp2util.h:1112:59: note: expanded from macro 'CPP2_UFCS_NONLOCAL'
 #define CPP2_UFCS_NONLOCAL(...)                           CPP2_UFCS_(,CPP2_UFCS_IDENTITY,CPP2_UFCS_IDENTITY,(),,__VA_ARGS__)
                                                           ^
-../../../include/cpp2util.h:955:66: note: expanded from macro 'CPP2_UFCS_'
+../../../include/cpp2util.h:1074:66: note: expanded from macro 'CPP2_UFCS_'
 #define CPP2_UFCS_(LAMBDADEFCAPT,SFINAE,MVFWD,QUALID,TEMPKW,...) \
                                                                  ^
 mixed-bugfix-for-ufcs-non-local.cpp2:27:29: error: a lambda expression cannot appear in this context
 [[nodiscard]] auto h() -> t<CPP2_UFCS_NONLOCAL(f)(o)> { return o;  }// Fails on Clang 12 (lambda in unevaluated context).
                             ^
-../../../include/cpp2util.h:993:59: note: expanded from macro 'CPP2_UFCS_NONLOCAL'
+../../../include/cpp2util.h:1112:59: note: expanded from macro 'CPP2_UFCS_NONLOCAL'
 #define CPP2_UFCS_NONLOCAL(...)                           CPP2_UFCS_(,CPP2_UFCS_IDENTITY,CPP2_UFCS_IDENTITY,(),,__VA_ARGS__)
                                                           ^
-../../../include/cpp2util.h:955:66: note: expanded from macro 'CPP2_UFCS_'
+../../../include/cpp2util.h:1074:66: note: expanded from macro 'CPP2_UFCS_'
 #define CPP2_UFCS_(LAMBDADEFCAPT,SFINAE,MVFWD,QUALID,TEMPKW,...) \
                                                                  ^
 mixed-bugfix-for-ufcs-non-local.cpp2:41:85: error: lambda expression in an unevaluated operand
   inline CPP2_CONSTEXPR bool u::c = [](cpp2::impl::in<std::type_identity_t<decltype(CPP2_UFCS_NONLOCAL(f)(o))>> x) mutable -> auto { return x; }(true);// Fails on Clang 12 (lambda in unevaluated context).
                                                                                     ^
-../../../include/cpp2util.h:993:59: note: expanded from macro 'CPP2_UFCS_NONLOCAL'
+../../../include/cpp2util.h:1112:59: note: expanded from macro 'CPP2_UFCS_NONLOCAL'
 #define CPP2_UFCS_NONLOCAL(...)                           CPP2_UFCS_(,CPP2_UFCS_IDENTITY,CPP2_UFCS_IDENTITY,(),,__VA_ARGS__)
                                                           ^
-../../../include/cpp2util.h:955:66: note: expanded from macro 'CPP2_UFCS_'
+../../../include/cpp2util.h:1074:66: note: expanded from macro 'CPP2_UFCS_'
 #define CPP2_UFCS_(LAMBDADEFCAPT,SFINAE,MVFWD,QUALID,TEMPKW,...) \
                                                                  ^
 13 errors generated.
diff --git a/regression-tests/test-results/clang-12/mixed-inspect-values.cpp.execution b/regression-tests/test-results/clang-12/mixed-inspect-values.cpp.execution
index 245368cfc..e7130e0f8 100644
--- a/regression-tests/test-results/clang-12/mixed-inspect-values.cpp.execution
+++ b/regression-tests/test-results/clang-12/mixed-inspect-values.cpp.execution
@@ -9,4 +9,4 @@ zero
 3
 integer -42
 xyzzy
-3
+(no match)
diff --git a/regression-tests/test-results/clang-12/pure2-bugfix-for-ufcs-noexcept.cpp.output b/regression-tests/test-results/clang-12/pure2-bugfix-for-ufcs-noexcept.cpp.output
index 455f6777b..63f630dff 100644
--- a/regression-tests/test-results/clang-12/pure2-bugfix-for-ufcs-noexcept.cpp.output
+++ b/regression-tests/test-results/clang-12/pure2-bugfix-for-ufcs-noexcept.cpp.output
@@ -1,10 +1,10 @@
 pure2-bugfix-for-ufcs-noexcept.cpp2:5:26: error: lambda expression in an unevaluated operand
   static_assert(noexcept(CPP2_UFCS(swap)(t(), t())));// Fails on Clang 12 (lambda in unevaluated context) and GCC 10 (static assertion failed)
                          ^
-../../../include/cpp2util.h:988:59: note: expanded from macro 'CPP2_UFCS'
+../../../include/cpp2util.h:1107:59: note: expanded from macro 'CPP2_UFCS'
 #define CPP2_UFCS(...)                                    CPP2_UFCS_(&,CPP2_UFCS_EMPTY,CPP2_UFCS_IDENTITY,(),,__VA_ARGS__)
                                                           ^
-../../../include/cpp2util.h:955:66: note: expanded from macro 'CPP2_UFCS_'
+../../../include/cpp2util.h:1074:66: note: expanded from macro 'CPP2_UFCS_'
 #define CPP2_UFCS_(LAMBDADEFCAPT,SFINAE,MVFWD,QUALID,TEMPKW,...) \
                                                                  ^
 1 error generated.
diff --git a/regression-tests/test-results/clang-12/pure2-bugfix-for-ufcs-sfinae.cpp.output b/regression-tests/test-results/clang-12/pure2-bugfix-for-ufcs-sfinae.cpp.output
index 00699f92d..98e3212be 100644
--- a/regression-tests/test-results/clang-12/pure2-bugfix-for-ufcs-sfinae.cpp.output
+++ b/regression-tests/test-results/clang-12/pure2-bugfix-for-ufcs-sfinae.cpp.output
@@ -1,19 +1,19 @@
 pure2-bugfix-for-ufcs-sfinae.cpp2:1:78: error: lambda expression in an unevaluated operand
 template<typename T> [[nodiscard]] auto f() -> std::type_identity_t<decltype(CPP2_UFCS_NONLOCAL(a)(T()))>;
                                                                              ^
-../../../include/cpp2util.h:993:59: note: expanded from macro 'CPP2_UFCS_NONLOCAL'
+../../../include/cpp2util.h:1112:59: note: expanded from macro 'CPP2_UFCS_NONLOCAL'
 #define CPP2_UFCS_NONLOCAL(...)                           CPP2_UFCS_(,CPP2_UFCS_IDENTITY,CPP2_UFCS_IDENTITY,(),,__VA_ARGS__)
                                                           ^
-../../../include/cpp2util.h:955:66: note: expanded from macro 'CPP2_UFCS_'
+../../../include/cpp2util.h:1074:66: note: expanded from macro 'CPP2_UFCS_'
 #define CPP2_UFCS_(LAMBDADEFCAPT,SFINAE,MVFWD,QUALID,TEMPKW,...) \
                                                                  ^
 pure2-bugfix-for-ufcs-sfinae.cpp2:1:78: error: lambda expression in an unevaluated operand
 template<typename T> [[nodiscard]] auto f() -> std::type_identity_t<decltype(CPP2_UFCS_NONLOCAL(a)(T()))>{}// Fails on Clang 12 (lambda in unevaluated context).
                                                                              ^
-../../../include/cpp2util.h:993:59: note: expanded from macro 'CPP2_UFCS_NONLOCAL'
+../../../include/cpp2util.h:1112:59: note: expanded from macro 'CPP2_UFCS_NONLOCAL'
 #define CPP2_UFCS_NONLOCAL(...)                           CPP2_UFCS_(,CPP2_UFCS_IDENTITY,CPP2_UFCS_IDENTITY,(),,__VA_ARGS__)
                                                           ^
-../../../include/cpp2util.h:955:66: note: expanded from macro 'CPP2_UFCS_'
+../../../include/cpp2util.h:1074:66: note: expanded from macro 'CPP2_UFCS_'
 #define CPP2_UFCS_(LAMBDADEFCAPT,SFINAE,MVFWD,QUALID,TEMPKW,...) \
                                                                  ^
 2 errors generated.
diff --git a/regression-tests/test-results/clang-12/pure2-is-with-free-functions-predicate.cpp.execution b/regression-tests/test-results/clang-12/pure2-is-with-free-functions-predicate.cpp.execution
new file mode 100644
index 000000000..c8a07e430
--- /dev/null
+++ b/regression-tests/test-results/clang-12/pure2-is-with-free-functions-predicate.cpp.execution
@@ -0,0 +1,6 @@
+3.140000 is double bigger than 3
+3.140000 is bigger than 3
+42 is integer bigger than 3
+42 is bigger than 3
+a is integer bigger than 3
+a is bigger than 3
diff --git a/regression-tests/test-results/clang-12/pure2-is-with-free-functions-predicate.cpp.output b/regression-tests/test-results/clang-12/pure2-is-with-free-functions-predicate.cpp.output
new file mode 100644
index 000000000..e69de29bb
diff --git a/regression-tests/test-results/clang-12/pure2-is-with-unnamed-predicates.cpp.execution b/regression-tests/test-results/clang-12/pure2-is-with-unnamed-predicates.cpp.execution
new file mode 100644
index 000000000..c8a07e430
--- /dev/null
+++ b/regression-tests/test-results/clang-12/pure2-is-with-unnamed-predicates.cpp.execution
@@ -0,0 +1,6 @@
+3.140000 is double bigger than 3
+3.140000 is bigger than 3
+42 is integer bigger than 3
+42 is bigger than 3
+a is integer bigger than 3
+a is bigger than 3
diff --git a/regression-tests/test-results/clang-12/pure2-is-with-unnamed-predicates.cpp.output b/regression-tests/test-results/clang-12/pure2-is-with-unnamed-predicates.cpp.output
new file mode 100644
index 000000000..e69de29bb
diff --git a/regression-tests/test-results/clang-12/pure2-is-with-variable-and-value.cpp.execution b/regression-tests/test-results/clang-12/pure2-is-with-variable-and-value.cpp.execution
new file mode 100644
index 000000000..a9bc0680a
--- /dev/null
+++ b/regression-tests/test-results/clang-12/pure2-is-with-variable-and-value.cpp.execution
@@ -0,0 +1,9 @@
+3.14: unknown
+42: 42
+WithOp(): unknown
+WithGenOp(): unknown
+Cmp(): comparable
+std::string("text"): text
+"text": text
+std::string_view("text"): text
+:std::vector = ('t','e','x','t','\0'): unknown
diff --git a/regression-tests/test-results/clang-12/pure2-is-with-variable-and-value.cpp.output b/regression-tests/test-results/clang-12/pure2-is-with-variable-and-value.cpp.output
new file mode 100644
index 000000000..e69de29bb
diff --git a/regression-tests/test-results/gcc-10/mixed-inspect-values.cpp.execution b/regression-tests/test-results/gcc-10/mixed-inspect-values.cpp.execution
index 245368cfc..e7130e0f8 100644
--- a/regression-tests/test-results/gcc-10/mixed-inspect-values.cpp.execution
+++ b/regression-tests/test-results/gcc-10/mixed-inspect-values.cpp.execution
@@ -9,4 +9,4 @@ zero
 3
 integer -42
 xyzzy
-3
+(no match)
diff --git a/regression-tests/test-results/gcc-10/pure2-is-with-free-functions-predicate.cpp.execution b/regression-tests/test-results/gcc-10/pure2-is-with-free-functions-predicate.cpp.execution
new file mode 100644
index 000000000..c8a07e430
--- /dev/null
+++ b/regression-tests/test-results/gcc-10/pure2-is-with-free-functions-predicate.cpp.execution
@@ -0,0 +1,6 @@
+3.140000 is double bigger than 3
+3.140000 is bigger than 3
+42 is integer bigger than 3
+42 is bigger than 3
+a is integer bigger than 3
+a is bigger than 3
diff --git a/regression-tests/test-results/gcc-10/pure2-is-with-free-functions-predicate.cpp.output b/regression-tests/test-results/gcc-10/pure2-is-with-free-functions-predicate.cpp.output
new file mode 100644
index 000000000..e69de29bb
diff --git a/regression-tests/test-results/gcc-10/pure2-is-with-unnamed-predicates.cpp.execution b/regression-tests/test-results/gcc-10/pure2-is-with-unnamed-predicates.cpp.execution
new file mode 100644
index 000000000..c8a07e430
--- /dev/null
+++ b/regression-tests/test-results/gcc-10/pure2-is-with-unnamed-predicates.cpp.execution
@@ -0,0 +1,6 @@
+3.140000 is double bigger than 3
+3.140000 is bigger than 3
+42 is integer bigger than 3
+42 is bigger than 3
+a is integer bigger than 3
+a is bigger than 3
diff --git a/regression-tests/test-results/gcc-10/pure2-is-with-unnamed-predicates.cpp.output b/regression-tests/test-results/gcc-10/pure2-is-with-unnamed-predicates.cpp.output
new file mode 100644
index 000000000..e69de29bb
diff --git a/regression-tests/test-results/gcc-10/pure2-is-with-variable-and-value.cpp.execution b/regression-tests/test-results/gcc-10/pure2-is-with-variable-and-value.cpp.execution
new file mode 100644
index 000000000..a9bc0680a
--- /dev/null
+++ b/regression-tests/test-results/gcc-10/pure2-is-with-variable-and-value.cpp.execution
@@ -0,0 +1,9 @@
+3.14: unknown
+42: 42
+WithOp(): unknown
+WithGenOp(): unknown
+Cmp(): comparable
+std::string("text"): text
+"text": text
+std::string_view("text"): text
+:std::vector = ('t','e','x','t','\0'): unknown
diff --git a/regression-tests/test-results/gcc-10/pure2-is-with-variable-and-value.cpp.output b/regression-tests/test-results/gcc-10/pure2-is-with-variable-and-value.cpp.output
new file mode 100644
index 000000000..e69de29bb
diff --git a/regression-tests/test-results/gcc-13/gcc-version.output b/regression-tests/test-results/gcc-13/gcc-version.output
index b06b2e08d..e0a9e3e94 100644
--- a/regression-tests/test-results/gcc-13/gcc-version.output
+++ b/regression-tests/test-results/gcc-13/gcc-version.output
@@ -1,4 +1,4 @@
-g++ (GCC) 13.2.1 20231011 (Red Hat 13.2.1-4)
+g++ (GCC) 13.2.1 20240316 (Red Hat 13.2.1-7)
 Copyright (C) 2023 Free Software Foundation, Inc.
 This is free software; see the source for copying conditions.  There is NO
 warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
diff --git a/regression-tests/test-results/gcc-13/mixed-bugfix-for-ufcs-non-local.cpp.output b/regression-tests/test-results/gcc-13/mixed-bugfix-for-ufcs-non-local.cpp.output
index 4d902ce2d..aa1b15b7a 100644
--- a/regression-tests/test-results/gcc-13/mixed-bugfix-for-ufcs-non-local.cpp.output
+++ b/regression-tests/test-results/gcc-13/mixed-bugfix-for-ufcs-non-local.cpp.output
@@ -1,41 +1,41 @@
 In file included from mixed-bugfix-for-ufcs-non-local.cpp:6:
-../../../include/cpp2util.h:956:1: error: lambda-expression in template parameter type
-  956 | [LAMBDADEFCAPT]< \
+../../../include/cpp2util.h:1075:1: error: lambda-expression in template parameter type
+ 1075 | [LAMBDADEFCAPT]< \
       | ^
-../../../include/cpp2util.h:993:59: note: in expansion of macro ‘CPP2_UFCS_’
-  993 | #define CPP2_UFCS_NONLOCAL(...)                           CPP2_UFCS_(,CPP2_UFCS_IDENTITY,CPP2_UFCS_IDENTITY,(),,__VA_ARGS__)
+../../../include/cpp2util.h:1112:59: note: in expansion of macro ‘CPP2_UFCS_’
+ 1112 | #define CPP2_UFCS_NONLOCAL(...)                           CPP2_UFCS_(,CPP2_UFCS_IDENTITY,CPP2_UFCS_IDENTITY,(),,__VA_ARGS__)
       |                                                           ^~~~~~~~~~
 mixed-bugfix-for-ufcs-non-local.cpp2:13:12: note: in expansion of macro ‘CPP2_UFCS_NONLOCAL’
 mixed-bugfix-for-ufcs-non-local.cpp2:13:36: error: template argument 1 is invalid
-../../../include/cpp2util.h:956:1: error: lambda-expression in template parameter type
-  956 | [LAMBDADEFCAPT]< \
+../../../include/cpp2util.h:1075:1: error: lambda-expression in template parameter type
+ 1075 | [LAMBDADEFCAPT]< \
       | ^
-../../../include/cpp2util.h:993:59: note: in expansion of macro ‘CPP2_UFCS_’
-  993 | #define CPP2_UFCS_NONLOCAL(...)                           CPP2_UFCS_(,CPP2_UFCS_IDENTITY,CPP2_UFCS_IDENTITY,(),,__VA_ARGS__)
+../../../include/cpp2util.h:1112:59: note: in expansion of macro ‘CPP2_UFCS_’
+ 1112 | #define CPP2_UFCS_NONLOCAL(...)                           CPP2_UFCS_(,CPP2_UFCS_IDENTITY,CPP2_UFCS_IDENTITY,(),,__VA_ARGS__)
       |                                                           ^~~~~~~~~~
 mixed-bugfix-for-ufcs-non-local.cpp2:21:12: note: in expansion of macro ‘CPP2_UFCS_NONLOCAL’
 mixed-bugfix-for-ufcs-non-local.cpp2:21:36: error: template argument 1 is invalid
-../../../include/cpp2util.h:956:1: error: lambda-expression in template parameter type
-  956 | [LAMBDADEFCAPT]< \
+../../../include/cpp2util.h:1075:1: error: lambda-expression in template parameter type
+ 1075 | [LAMBDADEFCAPT]< \
       | ^
-../../../include/cpp2util.h:993:59: note: in expansion of macro ‘CPP2_UFCS_’
-  993 | #define CPP2_UFCS_NONLOCAL(...)                           CPP2_UFCS_(,CPP2_UFCS_IDENTITY,CPP2_UFCS_IDENTITY,(),,__VA_ARGS__)
+../../../include/cpp2util.h:1112:59: note: in expansion of macro ‘CPP2_UFCS_’
+ 1112 | #define CPP2_UFCS_NONLOCAL(...)                           CPP2_UFCS_(,CPP2_UFCS_IDENTITY,CPP2_UFCS_IDENTITY,(),,__VA_ARGS__)
       |                                                           ^~~~~~~~~~
 mixed-bugfix-for-ufcs-non-local.cpp2:31:12: note: in expansion of macro ‘CPP2_UFCS_NONLOCAL’
 mixed-bugfix-for-ufcs-non-local.cpp2:31:36: error: template argument 1 is invalid
-../../../include/cpp2util.h:956:1: error: lambda-expression in template parameter type
-  956 | [LAMBDADEFCAPT]< \
+../../../include/cpp2util.h:1075:1: error: lambda-expression in template parameter type
+ 1075 | [LAMBDADEFCAPT]< \
       | ^
-../../../include/cpp2util.h:993:59: note: in expansion of macro ‘CPP2_UFCS_’
-  993 | #define CPP2_UFCS_NONLOCAL(...)                           CPP2_UFCS_(,CPP2_UFCS_IDENTITY,CPP2_UFCS_IDENTITY,(),,__VA_ARGS__)
+../../../include/cpp2util.h:1112:59: note: in expansion of macro ‘CPP2_UFCS_’
+ 1112 | #define CPP2_UFCS_NONLOCAL(...)                           CPP2_UFCS_(,CPP2_UFCS_IDENTITY,CPP2_UFCS_IDENTITY,(),,__VA_ARGS__)
       |                                                           ^~~~~~~~~~
 mixed-bugfix-for-ufcs-non-local.cpp2:33:12: note: in expansion of macro ‘CPP2_UFCS_NONLOCAL’
 mixed-bugfix-for-ufcs-non-local.cpp2:33:36: error: template argument 1 is invalid
-../../../include/cpp2util.h:956:1: error: lambda-expression in template parameter type
-  956 | [LAMBDADEFCAPT]< \
+../../../include/cpp2util.h:1075:1: error: lambda-expression in template parameter type
+ 1075 | [LAMBDADEFCAPT]< \
       | ^
-../../../include/cpp2util.h:993:59: note: in expansion of macro ‘CPP2_UFCS_’
-  993 | #define CPP2_UFCS_NONLOCAL(...)                           CPP2_UFCS_(,CPP2_UFCS_IDENTITY,CPP2_UFCS_IDENTITY,(),,__VA_ARGS__)
+../../../include/cpp2util.h:1112:59: note: in expansion of macro ‘CPP2_UFCS_’
+ 1112 | #define CPP2_UFCS_NONLOCAL(...)                           CPP2_UFCS_(,CPP2_UFCS_IDENTITY,CPP2_UFCS_IDENTITY,(),,__VA_ARGS__)
       |                                                           ^~~~~~~~~~
 mixed-bugfix-for-ufcs-non-local.cpp2:21:12: note: in expansion of macro ‘CPP2_UFCS_NONLOCAL’
 mixed-bugfix-for-ufcs-non-local.cpp2:21:36: error: template argument 1 is invalid
diff --git a/regression-tests/test-results/gcc-13/mixed-inspect-values.cpp.execution b/regression-tests/test-results/gcc-13/mixed-inspect-values.cpp.execution
index 245368cfc..e7130e0f8 100644
--- a/regression-tests/test-results/gcc-13/mixed-inspect-values.cpp.execution
+++ b/regression-tests/test-results/gcc-13/mixed-inspect-values.cpp.execution
@@ -9,4 +9,4 @@ zero
 3
 integer -42
 xyzzy
-3
+(no match)
diff --git a/regression-tests/test-results/gcc-13/pure2-is-with-free-functions-predicate.cpp.execution b/regression-tests/test-results/gcc-13/pure2-is-with-free-functions-predicate.cpp.execution
new file mode 100644
index 000000000..c8a07e430
--- /dev/null
+++ b/regression-tests/test-results/gcc-13/pure2-is-with-free-functions-predicate.cpp.execution
@@ -0,0 +1,6 @@
+3.140000 is double bigger than 3
+3.140000 is bigger than 3
+42 is integer bigger than 3
+42 is bigger than 3
+a is integer bigger than 3
+a is bigger than 3
diff --git a/regression-tests/test-results/gcc-13/pure2-is-with-free-functions-predicate.cpp.output b/regression-tests/test-results/gcc-13/pure2-is-with-free-functions-predicate.cpp.output
new file mode 100644
index 000000000..e69de29bb
diff --git a/regression-tests/test-results/gcc-13/pure2-is-with-unnamed-predicates.cpp.execution b/regression-tests/test-results/gcc-13/pure2-is-with-unnamed-predicates.cpp.execution
new file mode 100644
index 000000000..c8a07e430
--- /dev/null
+++ b/regression-tests/test-results/gcc-13/pure2-is-with-unnamed-predicates.cpp.execution
@@ -0,0 +1,6 @@
+3.140000 is double bigger than 3
+3.140000 is bigger than 3
+42 is integer bigger than 3
+42 is bigger than 3
+a is integer bigger than 3
+a is bigger than 3
diff --git a/regression-tests/test-results/gcc-13/pure2-is-with-unnamed-predicates.cpp.output b/regression-tests/test-results/gcc-13/pure2-is-with-unnamed-predicates.cpp.output
new file mode 100644
index 000000000..e69de29bb
diff --git a/regression-tests/test-results/gcc-13/pure2-is-with-variable-and-value.cpp.execution b/regression-tests/test-results/gcc-13/pure2-is-with-variable-and-value.cpp.execution
new file mode 100644
index 000000000..a9bc0680a
--- /dev/null
+++ b/regression-tests/test-results/gcc-13/pure2-is-with-variable-and-value.cpp.execution
@@ -0,0 +1,9 @@
+3.14: unknown
+42: 42
+WithOp(): unknown
+WithGenOp(): unknown
+Cmp(): comparable
+std::string("text"): text
+"text": text
+std::string_view("text"): text
+:std::vector = ('t','e','x','t','\0'): unknown
diff --git a/regression-tests/test-results/gcc-13/pure2-is-with-variable-and-value.cpp.output b/regression-tests/test-results/gcc-13/pure2-is-with-variable-and-value.cpp.output
new file mode 100644
index 000000000..e69de29bb
diff --git a/regression-tests/test-results/msvc-2022/MSVC-version.output b/regression-tests/test-results/msvc-2022/MSVC-version.output
index d8301eead..ba2c3c80f 100644
--- a/regression-tests/test-results/msvc-2022/MSVC-version.output
+++ b/regression-tests/test-results/msvc-2022/MSVC-version.output
@@ -1,3 +1,3 @@
-Microsoft (R) C/C++ Optimizing Compiler Version 19.39.33522 for x86
+Microsoft (R) C/C++ Optimizing Compiler Version 19.39.33523 for x86
 Copyright (C) Microsoft Corporation.  All rights reserved.
 
diff --git a/regression-tests/test-results/msvc-2022/mixed-inspect-values.cpp.execution b/regression-tests/test-results/msvc-2022/mixed-inspect-values.cpp.execution
index 245368cfc..e7130e0f8 100644
--- a/regression-tests/test-results/msvc-2022/mixed-inspect-values.cpp.execution
+++ b/regression-tests/test-results/msvc-2022/mixed-inspect-values.cpp.execution
@@ -9,4 +9,4 @@ zero
 3
 integer -42
 xyzzy
-3
+(no match)
diff --git a/regression-tests/test-results/msvc-2022/pure2-is-with-free-functions-predicate.cpp.execution b/regression-tests/test-results/msvc-2022/pure2-is-with-free-functions-predicate.cpp.execution
new file mode 100644
index 000000000..c8a07e430
--- /dev/null
+++ b/regression-tests/test-results/msvc-2022/pure2-is-with-free-functions-predicate.cpp.execution
@@ -0,0 +1,6 @@
+3.140000 is double bigger than 3
+3.140000 is bigger than 3
+42 is integer bigger than 3
+42 is bigger than 3
+a is integer bigger than 3
+a is bigger than 3
diff --git a/regression-tests/test-results/msvc-2022/pure2-is-with-free-functions-predicate.cpp.output b/regression-tests/test-results/msvc-2022/pure2-is-with-free-functions-predicate.cpp.output
new file mode 100644
index 000000000..e2ffd5e62
--- /dev/null
+++ b/regression-tests/test-results/msvc-2022/pure2-is-with-free-functions-predicate.cpp.output
@@ -0,0 +1 @@
+pure2-is-with-free-functions-predicate.cpp
diff --git a/regression-tests/test-results/msvc-2022/pure2-is-with-unnamed-predicates.cpp.execution b/regression-tests/test-results/msvc-2022/pure2-is-with-unnamed-predicates.cpp.execution
new file mode 100644
index 000000000..c8a07e430
--- /dev/null
+++ b/regression-tests/test-results/msvc-2022/pure2-is-with-unnamed-predicates.cpp.execution
@@ -0,0 +1,6 @@
+3.140000 is double bigger than 3
+3.140000 is bigger than 3
+42 is integer bigger than 3
+42 is bigger than 3
+a is integer bigger than 3
+a is bigger than 3
diff --git a/regression-tests/test-results/msvc-2022/pure2-is-with-unnamed-predicates.cpp.output b/regression-tests/test-results/msvc-2022/pure2-is-with-unnamed-predicates.cpp.output
new file mode 100644
index 000000000..67d1d00c8
--- /dev/null
+++ b/regression-tests/test-results/msvc-2022/pure2-is-with-unnamed-predicates.cpp.output
@@ -0,0 +1 @@
+pure2-is-with-unnamed-predicates.cpp
diff --git a/regression-tests/test-results/msvc-2022/pure2-is-with-variable-and-value.cpp.execution b/regression-tests/test-results/msvc-2022/pure2-is-with-variable-and-value.cpp.execution
new file mode 100644
index 000000000..a9bc0680a
--- /dev/null
+++ b/regression-tests/test-results/msvc-2022/pure2-is-with-variable-and-value.cpp.execution
@@ -0,0 +1,9 @@
+3.14: unknown
+42: 42
+WithOp(): unknown
+WithGenOp(): unknown
+Cmp(): comparable
+std::string("text"): text
+"text": text
+std::string_view("text"): text
+:std::vector = ('t','e','x','t','\0'): unknown
diff --git a/regression-tests/test-results/msvc-2022/pure2-is-with-variable-and-value.cpp.output b/regression-tests/test-results/msvc-2022/pure2-is-with-variable-and-value.cpp.output
new file mode 100644
index 000000000..4358a6f73
--- /dev/null
+++ b/regression-tests/test-results/msvc-2022/pure2-is-with-variable-and-value.cpp.output
@@ -0,0 +1 @@
+pure2-is-with-variable-and-value.cpp
diff --git a/regression-tests/test-results/pure2-is-with-free-functions-predicate.cpp b/regression-tests/test-results/pure2-is-with-free-functions-predicate.cpp
new file mode 100644
index 000000000..63dbefc80
--- /dev/null
+++ b/regression-tests/test-results/pure2-is-with-free-functions-predicate.cpp
@@ -0,0 +1,68 @@
+
+#define CPP2_IMPORT_STD          Yes
+
+//=== Cpp2 type declarations ====================================================
+
+
+#include "cpp2util.h"
+
+#line 1 "pure2-is-with-free-functions-predicate.cpp2"
+
+
+//=== Cpp2 type definitions and function declarations ===========================
+
+#line 1 "pure2-is-with-free-functions-predicate.cpp2"
+auto fun(auto const& v) -> void;
+
+#line 15 "pure2-is-with-free-functions-predicate.cpp2"
+[[nodiscard]] auto main() -> int;
+
+#line 21 "pure2-is-with-free-functions-predicate.cpp2"
+[[nodiscard]] auto pred_i(cpp2::impl::in<int> x) -> bool;
+
+#line 25 "pure2-is-with-free-functions-predicate.cpp2"
+[[nodiscard]] auto pred_d(cpp2::impl::in<double> x) -> bool;
+
+#line 29 "pure2-is-with-free-functions-predicate.cpp2"
+[[nodiscard]] auto pred_(auto const& x) -> bool;
+
+//=== Cpp2 function definitions =================================================
+
+#line 1 "pure2-is-with-free-functions-predicate.cpp2"
+auto fun(auto const& v) -> void{
+#line 2 "pure2-is-with-free-functions-predicate.cpp2"
+    if (cpp2::impl::is(v, (pred_i))) {
+        std::cout << (cpp2::to_string(v) + " is integer bigger than 3") << std::endl;
+    }
+
+    if (cpp2::impl::is(v, (pred_d))) {
+        std::cout << (cpp2::to_string(v) + " is double bigger than 3") << std::endl;
+    }
+
+    if (cpp2::impl::is(v, (pred_))) {
+        std::cout << (cpp2::to_string(v) + " is bigger than 3") << std::endl;
+    }
+}
+
+#line 15 "pure2-is-with-free-functions-predicate.cpp2"
+[[nodiscard]] auto main() -> int{
+    fun(3.14);
+    fun(42);
+    fun('a');
+}
+
+#line 21 "pure2-is-with-free-functions-predicate.cpp2"
+[[nodiscard]] auto pred_i(cpp2::impl::in<int> x) -> bool{
+    return cpp2::impl::cmp_greater(x,3); 
+}
+
+#line 25 "pure2-is-with-free-functions-predicate.cpp2"
+[[nodiscard]] auto pred_d(cpp2::impl::in<double> x) -> bool{
+    return cpp2::impl::cmp_greater(x,3); 
+}
+
+#line 29 "pure2-is-with-free-functions-predicate.cpp2"
+[[nodiscard]] auto pred_(auto const& x) -> bool{
+    return cpp2::impl::cmp_greater(x,3); 
+}
+
diff --git a/regression-tests/test-results/pure2-is-with-free-functions-predicate.cpp2.output b/regression-tests/test-results/pure2-is-with-free-functions-predicate.cpp2.output
new file mode 100644
index 000000000..cd9cc4aec
--- /dev/null
+++ b/regression-tests/test-results/pure2-is-with-free-functions-predicate.cpp2.output
@@ -0,0 +1,2 @@
+pure2-is-with-free-functions-predicate.cpp2... ok (all Cpp2, passes safety checks)
+
diff --git a/regression-tests/test-results/pure2-is-with-unnamed-predicates.cpp b/regression-tests/test-results/pure2-is-with-unnamed-predicates.cpp
new file mode 100644
index 000000000..5689749ac
--- /dev/null
+++ b/regression-tests/test-results/pure2-is-with-unnamed-predicates.cpp
@@ -0,0 +1,44 @@
+
+#define CPP2_IMPORT_STD          Yes
+
+//=== Cpp2 type declarations ====================================================
+
+
+#include "cpp2util.h"
+
+#line 1 "pure2-is-with-unnamed-predicates.cpp2"
+
+
+//=== Cpp2 type definitions and function declarations ===========================
+
+#line 1 "pure2-is-with-unnamed-predicates.cpp2"
+auto fun(auto const& v) -> void;
+
+#line 15 "pure2-is-with-unnamed-predicates.cpp2"
+[[nodiscard]] auto main() -> int;
+
+//=== Cpp2 function definitions =================================================
+
+#line 1 "pure2-is-with-unnamed-predicates.cpp2"
+auto fun(auto const& v) -> void{
+#line 2 "pure2-is-with-unnamed-predicates.cpp2"
+    if (cpp2::impl::is(v, ([](cpp2::impl::in<int> x) mutable -> auto { return cpp2::impl::cmp_greater(x,3); }))) {
+        std::cout << (cpp2::to_string(v) + " is integer bigger than 3") << std::endl;
+    }
+
+    if (cpp2::impl::is(v, ([](cpp2::impl::in<double> x) mutable -> auto { return cpp2::impl::cmp_greater(x,3); }))) {
+        std::cout << (cpp2::to_string(v) + " is double bigger than 3") << std::endl;
+    }
+
+    if (cpp2::impl::is(v, ([](auto const& x) mutable -> auto { return cpp2::impl::cmp_greater(x,3); }))) {
+        std::cout << (cpp2::to_string(v) + " is bigger than 3") << std::endl;
+    }
+}
+
+#line 15 "pure2-is-with-unnamed-predicates.cpp2"
+[[nodiscard]] auto main() -> int{
+    fun(3.14);
+    fun(42);
+    fun('a');
+}
+
diff --git a/regression-tests/test-results/pure2-is-with-unnamed-predicates.cpp2.output b/regression-tests/test-results/pure2-is-with-unnamed-predicates.cpp2.output
new file mode 100644
index 000000000..6065d9729
--- /dev/null
+++ b/regression-tests/test-results/pure2-is-with-unnamed-predicates.cpp2.output
@@ -0,0 +1,2 @@
+pure2-is-with-unnamed-predicates.cpp2... ok (all Cpp2, passes safety checks)
+
diff --git a/regression-tests/test-results/pure2-is-with-variable-and-value.cpp b/regression-tests/test-results/pure2-is-with-variable-and-value.cpp
new file mode 100644
index 000000000..c178e96a6
--- /dev/null
+++ b/regression-tests/test-results/pure2-is-with-variable-and-value.cpp
@@ -0,0 +1,104 @@
+
+#define CPP2_IMPORT_STD          Yes
+
+//=== Cpp2 type declarations ====================================================
+
+
+#include "cpp2util.h"
+
+#line 1 "pure2-is-with-variable-and-value.cpp2"
+
+#line 26 "pure2-is-with-variable-and-value.cpp2"
+class WithOp;
+    
+
+#line 30 "pure2-is-with-variable-and-value.cpp2"
+class WithGenOp;
+    
+
+#line 39 "pure2-is-with-variable-and-value.cpp2"
+class Cmp;
+    
+
+//=== Cpp2 type definitions and function declarations ===========================
+
+#line 1 "pure2-is-with-variable-and-value.cpp2"
+auto fun(auto const& name, auto const& v) -> void;
+
+#line 14 "pure2-is-with-variable-and-value.cpp2"
+[[nodiscard]] auto main() -> int;
+
+#line 26 "pure2-is-with-variable-and-value.cpp2"
+class WithOp {
+    public: [[nodiscard]] auto op_is(cpp2::impl::in<int> x) const& -> auto;
+    public: WithOp() = default;
+    public: WithOp(WithOp const&) = delete; /* No 'that' constructor, suppress copy */
+    public: auto operator=(WithOp const&) -> void = delete;
+
+#line 28 "pure2-is-with-variable-and-value.cpp2"
+};
+
+class WithGenOp {
+    public: [[nodiscard]] auto op_is(auto const& x) const& -> bool;
+    public: WithGenOp() = default;
+    public: WithGenOp(WithGenOp const&) = delete; /* No 'that' constructor, suppress copy */
+    public: auto operator=(WithGenOp const&) -> void = delete;
+
+
+#line 37 "pure2-is-with-variable-and-value.cpp2"
+};
+
+class Cmp {
+    public: [[nodiscard]] auto operator==(cpp2::impl::in<int> x) const& -> bool;
+    public: Cmp() = default;
+    public: Cmp(Cmp const&) = delete; /* No 'that' constructor, suppress copy */
+    public: auto operator=(Cmp const&) -> void = delete;
+
+#line 41 "pure2-is-with-variable-and-value.cpp2"
+};
+
+
+//=== Cpp2 function definitions =================================================
+
+#line 1 "pure2-is-with-variable-and-value.cpp2"
+auto fun(auto const& name, auto const& v) -> void{
+#line 2 "pure2-is-with-variable-and-value.cpp2"
+    std::cout << name << ": " << 
+                [&] () -> std::string { auto&& _expr = v;
+                if (cpp2::impl::is(_expr, (42))) { if constexpr( requires{"42";} ) if constexpr( std::is_convertible_v<CPP2_TYPEOF(("42")),std::string> ) return "42"; else return std::string{}; else return std::string{}; }
+                else if (cpp2::impl::is(_expr, 123)) { if constexpr( requires{"op_is";} ) if constexpr( std::is_convertible_v<CPP2_TYPEOF(("op_is")),std::string> ) return "op_is"; else return std::string{}; else return std::string{}; }
+                else if (cpp2::impl::is(_expr, -123)) { if constexpr( requires{"generic op_is";} ) if constexpr( std::is_convertible_v<CPP2_TYPEOF(("generic op_is")),std::string> ) return "generic op_is"; else return std::string{}; else return std::string{}; }
+                else if (cpp2::impl::is(_expr, 4321)) { if constexpr( requires{"comparable";} ) if constexpr( std::is_convertible_v<CPP2_TYPEOF(("comparable")),std::string> ) return "comparable"; else return std::string{}; else return std::string{}; }
+                else if (cpp2::impl::is(_expr, "text")) { if constexpr( requires{"text";} ) if constexpr( std::is_convertible_v<CPP2_TYPEOF(("text")),std::string> ) return "text"; else return std::string{}; else return std::string{}; }
+                else return "unknown"; }
+              () 
+              << std::endl;
+}
+
+#line 14 "pure2-is-with-variable-and-value.cpp2"
+[[nodiscard]] auto main() -> int{
+    fun("3.14", 3.14);
+    fun("42", 42);
+    fun("WithOp()", WithOp());
+    fun("WithGenOp()", WithGenOp());
+    fun("Cmp()", Cmp());
+    fun("std::string(\"text\")", std::string("text"));
+    fun("\"text\"", "text");
+    fun("std::string_view(\"text\")", std::string_view("text"));
+    fun(":std::vector = ('t','e','x','t','\\0')", std::vector{'t', 'e', 'x', 't', '\0'});
+}
+
+#line 27 "pure2-is-with-variable-and-value.cpp2"
+    [[nodiscard]] auto WithOp::op_is(cpp2::impl::in<int> x) const& -> auto { return x == 123;  }
+
+#line 31 "pure2-is-with-variable-and-value.cpp2"
+    [[nodiscard]] auto WithGenOp::op_is(auto const& x) const& -> bool{
+        if constexpr (std::convertible_to<decltype(x),int>) {
+            return x == -123; 
+        }
+        return false; 
+    }
+
+#line 40 "pure2-is-with-variable-and-value.cpp2"
+    [[nodiscard]] auto Cmp::operator==(cpp2::impl::in<int> x) const& -> bool { return x == 4321;  }
+
diff --git a/regression-tests/test-results/pure2-is-with-variable-and-value.cpp2.output b/regression-tests/test-results/pure2-is-with-variable-and-value.cpp2.output
new file mode 100644
index 000000000..73c639fb2
--- /dev/null
+++ b/regression-tests/test-results/pure2-is-with-variable-and-value.cpp2.output
@@ -0,0 +1,2 @@
+pure2-is-with-variable-and-value.cpp2... ok (all Cpp2, passes safety checks)
+