Update isfinite declaration to be constexpr for c++23 only

Dependent function std::isfinite is constexpr for c++23. https://en.cppreference.com/w/cpp/numeric/math/isfinite Fix fmtlib#3745
hchataing · Dec 9, 2023 · 04338ce · 04338ce
1 parent dee0dbf
commit 04338ce
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Showing 5 changed files with 12 additions and 6 deletions.
diff --git a/include/fmt/core.h b/include/fmt/core.h
@@ -113,6 +113,12 @@
 #  define FMT_CONSTEXPR20
 #endif
 
+#if (FMT_CPLUSPLUS >= 202302L)
+#  define FMT_CONSTEXPR23 constexpr
+#else
+#  define FMT_CONSTEXPR23
+#endif
+
 // Check if constexpr std::char_traits<>::{compare,length} are supported.
 #if defined(__GLIBCXX__)
 #  if FMT_CPLUSPLUS >= 201703L && defined(_GLIBCXX_RELEASE) && \

diff --git a/include/fmt/format.h b/include/fmt/format.h
@@ -2750,7 +2750,7 @@ struct has_isfinite<T, enable_if_t<sizeof(std::isfinite(T())) != 0>>
 
 template <typename T, FMT_ENABLE_IF(std::is_floating_point<T>::value&&
                                         has_isfinite<T>::value)>
-FMT_CONSTEXPR20 bool isfinite(T value) {
+FMT_CONSTEXPR23 bool isfinite(T value) {
   constexpr T inf = T(std::numeric_limits<double>::infinity());
   if (is_constant_evaluated())
     return !detail::isnan(value) && value < inf && value > -inf;
@@ -3587,7 +3587,7 @@ FMT_CONSTEXPR20 auto format_float(Float value, int precision, float_specs specs,
   return exp;
 }
 template <typename Char, typename OutputIt, typename T>
-FMT_CONSTEXPR20 auto write_float(OutputIt out, T value,
+FMT_CONSTEXPR23 auto write_float(OutputIt out, T value,
                                  format_specs<Char> specs, locale_ref loc)
     -> OutputIt {
   float_specs fspecs = parse_float_type_spec(specs);
@@ -3637,7 +3637,7 @@ FMT_CONSTEXPR20 auto write_float(OutputIt out, T value,
 
 template <typename Char, typename OutputIt, typename T,
           FMT_ENABLE_IF(is_floating_point<T>::value)>
-FMT_CONSTEXPR20 auto write(OutputIt out, T value, format_specs<Char> specs,
+FMT_CONSTEXPR23 auto write(OutputIt out, T value, format_specs<Char> specs,
                            locale_ref loc = {}) -> OutputIt {
   if (const_check(!is_supported_floating_point(value))) return out;
   return specs.localized && write_loc(out, value, specs, loc)

diff --git a/test/compile-fp-test.cc b/test/compile-fp-test.cc
@@ -11,7 +11,7 @@
 #if defined(__cpp_lib_bit_cast) && __cpp_lib_bit_cast >= 201806 && \
     defined(__cpp_constexpr) && __cpp_constexpr >= 201907 &&       \
     defined(__cpp_constexpr_dynamic_alloc) &&                      \
-    __cpp_constexpr_dynamic_alloc >= 201907 && FMT_CPLUSPLUS >= 202002L
+    __cpp_constexpr_dynamic_alloc >= 201907 && FMT_CPLUSPLUS >= 202302L
 
 template <size_t max_string_length, typename Char = char> struct test_string {
   template <typename T> constexpr bool operator==(const T& rhs) const noexcept {

diff --git a/test/compile-test.cc b/test/compile-test.cc
@@ -208,7 +208,7 @@ TEST(compile_test, constexpr_formatted_size) {
   FMT_CONSTEXPR20 size_t padded_size =
       fmt::formatted_size(FMT_COMPILE("{:*^6}"), 42);
   EXPECT_EQ(padded_size, 6);
-  FMT_CONSTEXPR20 size_t float_size =
+  FMT_CONSTEXPR23 size_t float_size =
       fmt::formatted_size(FMT_COMPILE("{:.3}"), 12.345);
   EXPECT_EQ(float_size, 4);
   FMT_CONSTEXPR20 size_t str_size =

diff --git a/test/format-test.cc b/test/format-test.cc
@@ -91,7 +91,7 @@ template <typename Float> void check_isfinite() {
   EXPECT_TRUE(isfinite(Float(fmt::detail::max_value<double>())));
   // Use double because std::numeric_limits is broken for __float128.
   using limits = std::numeric_limits<double>;
-  FMT_CONSTEXPR20 auto result = isfinite(Float(limits::infinity()));
+  FMT_CONSTEXPR23 auto result = isfinite(Float(limits::infinity()));
   EXPECT_FALSE(result);
   EXPECT_FALSE(isfinite(Float(limits::infinity())));
   EXPECT_FALSE(isfinite(Float(-limits::infinity())));