Support G++, support string type as template argument for convert()

1 files changed, 19 insertions, 2 deletions

diff --git a/include/unicode.h b/include/unicode.h
index d6f8e51..171496e 100644
--- a/include/unicode.h
+++ b/include/unicode.h
@@ -12,6 +12,7 @@
 #include <memory>
 #include <stdexcept>
 #include <string>
+#include <type_traits>
 #include <unordered_map>
 
 #ifdef __cpp_char8_t
@@ -526,7 +527,7 @@ namespace unicode {
  typedef UTF<utf_iterator<char32_t>, utf_back_insert_iterator<char32_t>> UTF_32;
 
  // From and To are facets
- template<typename From, typename To>
+ template<typename From, typename To, std::enable_if_t<std::is_empty<From>::value && std::is_empty<To>::value, bool> = true>
  std::basic_string<typename To::value_type> convert(const std::basic_string<typename From::value_type>& s)
  {
   std::basic_string<typename To::value_type> result;
@@ -561,7 +562,9 @@ namespace unicode {
  };
 
  // From and To are from: utf8_t, char16_t and char32_t
- template<typename From, typename To>
+ template<typename From, typename To,
+  std::enable_if_t<std::is_trivial<From>::value && std::is_trivial<To>::value, bool> = true
+ >
  std::basic_string<To> convert(const std::basic_string<From>& s)
  {
   typedef UTF<utf_iterator<From>, utf_back_insert_iterator<To>> UTF_Trait;
@@ -573,6 +576,20 @@ namespace unicode {
   return result;
  }
 
+ template<typename FromContainer, typename ToContainer,
+  std::enable_if_t<!std::is_empty<FromContainer>::value && !std::is_empty<ToContainer>::value, bool> = true
+ >
+ ToContainer convert(const FromContainer& s)
+ {
+  typedef UTF<utf_iterator<typename FromContainer::value_type>, utf_back_insert_iterator<typename ToContainer::value_type>> UTF_Trait;
+  
+  ToContainer result;
+
+  std::copy(UTF_Trait::begin(s), UTF_Trait::end(s), UTF_Trait::back_inserter(result));
+
+  return result;
+ }
+
  // basic type version
  template<typename T>
  bool is_valid_utf(const std::basic_string<T>& s)