Replace asserts in string utils

Author: thk123

src/util/string_utils.cpp

@@ -7,6 +7,7 @@ Author: Daniel Poetzl
 \*******************************************************************/
 
 #include "string_utils.h"
+#include "invariant.h"
 
 #include <cassert>
 #include <cctype>
@@ -51,8 +52,14 @@ void split_string(
   bool strip,
   bool remove_empty)
 {
-  assert(result.empty());
-  assert(!strip || !std::isspace(delim));
+  if(!result.empty())
+    throw std::invalid_argument("result: vector must be empty");
+
+  if(strip && std::isspace(delim))
+  {
+    throw std::invalid_argument(
+      "delim can't be a space character if using strip");
+  }
 
   if(s.empty())
   {
@@ -61,7 +68,7 @@ void split_string(
   }
 
   std::string::size_type n=s.length();
-  assert(n>0);
+  INVARIANT(n > 0, "Empty string case should already be handled");
 
   std::string::size_type start=0;
   std::string::size_type i;
@@ -101,7 +108,11 @@ void split_string(
   std::string &right,
   bool strip)
 {
-  assert(!std::isspace(delim));
+  if(strip && std::isspace(delim))
+  {
+    throw std::invalid_argument(
+      "delim can't be a space character if using strip");
+  }
 
   std::vector<std::string> result;