Move FMT_USE_FLOAT and friends to fmt/format.h

include/fmt/core.h

@@ -284,7 +284,8 @@ FMT_NORETURN FMT_API void assert_fail(const char* file, int line,
 
 #ifndef FMT_ASSERT
 #  ifdef NDEBUG
-#    define FMT_ASSERT(condition, message)
+     // FMT_ASSERT is not empty to avoid -Werror=empty-body.
+#    define FMT_ASSERT(condition, message) ((void)0)
 #  else
 #    define FMT_ASSERT(condition, message)                                    \
       ((condition) /* void() fails with -Winvalid-constexpr on clang 4.0.1 */ \
@@ -316,18 +317,6 @@ struct int128_t {};
 struct uint128_t {};
 #endif
 
-#ifndef FMT_USE_FLOAT
-#  define FMT_USE_FLOAT 1
-#endif
-
-#ifndef FMT_USE_DOUBLE
-#  define FMT_USE_DOUBLE 1
-#endif
-
-#ifndef FMT_USE_LONG_DOUBLE
-#  define FMT_USE_LONG_DOUBLE 1
-#endif
-
 // Casts a nonnegative integer to unsigned.
 template <typename Int>
 FMT_CONSTEXPR typename std::make_unsigned<Int>::type to_unsigned(Int value) {

include/fmt/format.h

@@ -138,6 +138,18 @@ FMT_END_NAMESPACE
 #  endif
 #endif
 
+#ifndef FMT_USE_FLOAT
+#  define FMT_USE_FLOAT 1
+#endif
+
+#ifndef FMT_USE_DOUBLE
+#  define FMT_USE_DOUBLE 1
+#endif
+
+#ifndef FMT_USE_LONG_DOUBLE
+#  define FMT_USE_LONG_DOUBLE 1
+#endif
+
 // __builtin_clz is broken in clang with Microsoft CodeGen:
 // https://github.com/fmtlib/fmt/issues/519
 #if (FMT_GCC_VERSION || FMT_HAS_BUILTIN(__builtin_clz)) && !FMT_MSC_VER
@@ -1893,11 +1905,10 @@ class arg_formatter_base {
 
   template <typename T, FMT_ENABLE_IF(std::is_floating_point<T>::value)>
   iterator operator()(T value) {
-    if (const_check(!is_supported_floating_point(value))) {
-      FMT_ASSERT(false, "unsupported float argument type");
-      return out();
-    }
+    if (const_check(is_supported_floating_point(value)))
       writer_.write(value, specs_ ? *specs_ : format_specs());
+    else
+      FMT_ASSERT(false, "unsupported float argument type");
     return out();
   }