Allowed split_string to be used on whitespace if not also trying to strip

Also improved comments as I assumed strip would remove whitespace from
throughout the string but actually only does the final string

Author: thk123

src/util/string_utils.cpp

@@ -12,6 +12,10 @@ Author: Daniel Poetzl
 #include <cctype>
 #include <algorithm>
 
+/// Remove all whitespace characters from the end of a string. Whitespace
+/// in the middle of the string is left unchanged
+/// \param s: the string to strip
+/// \return The stripped string
 std::string strip_string(const std::string &s)
 {
   auto pred=[](char c){ return std::isspace(c); };
@@ -38,7 +42,7 @@ void split_string(
   bool remove_empty)
 {
   assert(result.empty());
-  assert(!std::isspace(delim));
+  assert(!strip || !std::isspace(delim));
 
   if(s.empty())
   {

src/util/string_utils.h

@@ -18,10 +18,10 @@ std::string strip_string(const std::string &s);
 
 void split_string(
   const std::string &s,
-  char delim, // must not be a whitespace character
+  char delim, // must not be a whitespace character if strip is enabled
   std::vector<std::string> &result,
-  bool strip=false, // strip whitespace from elements
-  bool remove_empty=false); // remove empty elements
+  bool strip = false,         // strip whitespace from the end of elements
+  bool remove_empty = false); // remove empty elements
 
 void split_string(
   const std::string &s,