Support C++17

3 files changed, 32 insertions, 19 deletions

diff --git a/Makefile b/Makefile
index 6bc26a8..31af4e2 100644
--- a/Makefile
+++ b/Makefile
@@ -1,12 +1,19 @@
 CXX=clang++-11
 #CXX=g++-10
 
+STANDARD=c++17
+#STANDARD=c++20
+
 CXXFLAGS=-O0 -g -D_DEBUG
 #CXXFLAGS=-O2 -DNDEBUG
 
-CXXFLAGS+=-Wall -Iinclude -std=c++20
+CXXFLAGS+=-Wall -Iinclude -std=$(STANDARD)
 
 ifeq ($(CXX),clang++-11)
+COMPILER_SUITE=clang
+endif
+
+ifeq ($(COMPILER_SUITE),clang)
 CXXFLAGS+=-stdlib=libc++
 endif
 
@@ -16,7 +23,7 @@ LDLIBS+=\
 -lboost_timer \
 -lboost_system \
 
-ifeq ($(CXX),clang++-11)
+ifeq ($(COMPILER_SUITE),clang)
 LIBS+= \
 -fuse-ld=lld-11 \
 -lc++ \
diff --git a/include/unicode.h b/include/unicode.h
index 908c75f..9e0132b 100644
--- a/include/unicode.h
+++ b/include/unicode.h
@@ -8,6 +8,9 @@
 
 #ifdef __cpp_char8_t
 // char8_t available
+ typedef char8_t utf8_t;
+#else
+ typedef char utf8_t;
 #endif
 
 namespace unicode {
@@ -21,7 +24,7 @@ namespace unicode {
 
 }
 
-namespace {
+namespace unicode::detail {
 
  using namespace std::string_literals;
 
@@ -107,29 +110,30 @@ namespace {
    return static_cast<char32_t>(b & (0b1111111 >> n)) << ((n - 1) * 6);
   }
 
+  // GCC Bug: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85282
   // specialization for UTF-8
   template<>
-  void calculate_value<char8_t>()
+  void calculate_value<utf8_t>()
   {
    size_t remaining{remaining_code_units()};
    
    if (!remaining)
     return;
 
-   char8_t byte0 {get_code_unit<0>()};
+   utf8_t byte0 {get_code_unit<0>()};
    if (byte0 & 0x80) { // 2-4 bytes
     if (remaining >= 2) {
-     char8_t byte1 {get_code_unit<1>()};
+     utf8_t byte1 {get_code_unit<1>()};
      if (is_byte0_of<2>(byte0) && is_continuation_byte(byte1)) { // 2 bytes
       value = value_byte0_of<2>(byte0) | continuation_value(byte1);
       sequence_length = 2;
      } else if (remaining >= 3) {
-      char8_t byte2 {get_code_unit<2>()};
+      utf8_t byte2 {get_code_unit<2>()};
       if (is_byte0_of<3>(byte0) && is_continuation_byte(byte1, byte2)) { // 3 bytes
        value = value_byte0_of<3>(byte0) | continuation_value(byte1, byte2);
        sequence_length = 3;
       } else if (remaining >= 4) {
-       char8_t byte3 {get_code_unit<3>()};
+       utf8_t byte3 {get_code_unit<3>()};
        if (is_byte0_of<4>(byte0) && is_continuation_byte(byte1, byte2, byte3)) { // 4 bytes
         value = value_byte0_of<4>(byte0) | continuation_value(byte1, byte2, byte3);
         sequence_length = 4;
@@ -262,7 +266,7 @@ namespace {
   // specialization for UTF-8
   // append utf-8 byte sequence
   template<>
-  reference operator=<char8_t>(const char32_t& value)
+  reference operator=<utf8_t>(const char32_t& value)
   {
    if (value < 0x80) { // 1 byte
     s.push_back(value);
@@ -323,15 +327,17 @@ namespace {
 
 namespace unicode {
 
-template<typename From, typename To>
-std::basic_string<To> utf_to_utf(const std::basic_string<From>& s)
-{
- std::basic_string<To> result;
+ using namespace detail;
 
- std::copy(utf_begin<From>(s), utf_end<From>(s), utf_back_inserter<To>(result));
+ template<typename From, typename To>
+ std::basic_string<To> utf_to_utf(const std::basic_string<From>& s)
+ {
+  std::basic_string<To> result;
 
- return result;
-}
+  std::copy(utf_begin<From>(s), utf_end<From>(s), utf_back_inserter<To>(result));
+
+  return result;
+ }
 
 } // namespace unicode
 
diff --git a/src/test-unicode.cpp b/src/test-unicode.cpp
index 2dfabef..05370c7 100644
--- a/src/test-unicode.cpp
+++ b/src/test-unicode.cpp
@@ -18,7 +18,7 @@
 
 using namespace std::chrono_literals;
 
-typedef std::tuple<std::basic_string<char8_t>, std::basic_string<char16_t>, std::basic_string<char32_t>> types_collection_type;
+typedef std::tuple<std::basic_string<utf8_t>, std::basic_string<char16_t>, std::basic_string<char32_t>> types_collection_type;
 
 // create tuple of the same string, in UTF-8, UTF-16 and UTF-32
 #define SUCCESS_TUPLE(x) {u8 ## x, u ## x, U ## x}
@@ -34,7 +34,7 @@ std::vector<types_collection_type> success_sets {
 };
 
 // Error cases: throwing upon convert to all other types
-std::vector<std::basic_string<char8_t>> failure_strings_char8_t {
+std::vector<std::basic_string<utf8_t>> failure_strings_char8_t {
  u8"\x80", // utf-8 continuation byte
  u8"\x81", // utf-8 continuation byte
  u8"\xc3ä", // initial byte of utf-8 "ä", followed by valid utf-8 "ä"
@@ -56,7 +56,7 @@ std::vector<std::basic_string<char32_t>> failure_strings_char32_t {
 // output operators must be in same namespace as the type itself
 namespace std {
 
-std::ostream& operator<<(std::ostream& os, std::basic_string<char8_t> const& s)
+std::ostream& operator<<(std::ostream& os, std::basic_string<utf8_t> const& s)
 {
  os << "[";
  for (auto& c: s)