remove fallback to inline in FMT_CONSTEXPR(20), place needed inline specifiers

in headers

include/fmt/chrono.h

@@ -456,27 +456,61 @@ namespace detail {
 template <typename Period> FMT_CONSTEXPR const char* get_units() {
   return nullptr;
 }
-template <> FMT_CONSTEXPR const char* get_units<std::atto>() { return "as"; }
-template <> FMT_CONSTEXPR const char* get_units<std::femto>() { return "fs"; }
-template <> FMT_CONSTEXPR const char* get_units<std::pico>() { return "ps"; }
-template <> FMT_CONSTEXPR const char* get_units<std::nano>() { return "ns"; }
-template <> FMT_CONSTEXPR const char* get_units<std::micro>() { return "µs"; }
-template <> FMT_CONSTEXPR const char* get_units<std::milli>() { return "ms"; }
-template <> FMT_CONSTEXPR const char* get_units<std::centi>() { return "cs"; }
-template <> FMT_CONSTEXPR const char* get_units<std::deci>() { return "ds"; }
-template <> FMT_CONSTEXPR const char* get_units<std::ratio<1>>() { return "s"; }
-template <> FMT_CONSTEXPR const char* get_units<std::deca>() { return "das"; }
-template <> FMT_CONSTEXPR const char* get_units<std::hecto>() { return "hs"; }
-template <> FMT_CONSTEXPR const char* get_units<std::kilo>() { return "ks"; }
-template <> FMT_CONSTEXPR const char* get_units<std::mega>() { return "Ms"; }
-template <> FMT_CONSTEXPR const char* get_units<std::giga>() { return "Gs"; }
-template <> FMT_CONSTEXPR const char* get_units<std::tera>() { return "Ts"; }
-template <> FMT_CONSTEXPR const char* get_units<std::peta>() { return "Ps"; }
-template <> FMT_CONSTEXPR const char* get_units<std::exa>() { return "Es"; }
-template <> FMT_CONSTEXPR const char* get_units<std::ratio<60>>() {
+template <> FMT_CONSTEXPR inline const char* get_units<std::atto>() {
+  return "as";
+}
+template <> FMT_CONSTEXPR inline const char* get_units<std::femto>() {
+  return "fs";
+}
+template <> FMT_CONSTEXPR inline const char* get_units<std::pico>() {
+  return "ps";
+}
+template <> FMT_CONSTEXPR inline const char* get_units<std::nano>() {
+  return "ns";
+}
+template <> FMT_CONSTEXPR inline const char* get_units<std::micro>() {
+  return "µs";
+}
+template <> FMT_CONSTEXPR inline const char* get_units<std::milli>() {
+  return "ms";
+}
+template <> FMT_CONSTEXPR inline const char* get_units<std::centi>() {
+  return "cs";
+}
+template <> FMT_CONSTEXPR inline const char* get_units<std::deci>() {
+  return "ds";
+}
+template <> FMT_CONSTEXPR inline const char* get_units<std::ratio<1>>() {
+  return "s";
+}
+template <> FMT_CONSTEXPR inline const char* get_units<std::deca>() {
+  return "das";
+}
+template <> FMT_CONSTEXPR inline const char* get_units<std::hecto>() {
+  return "hs";
+}
+template <> FMT_CONSTEXPR inline const char* get_units<std::kilo>() {
+  return "ks";
+}
+template <> FMT_CONSTEXPR inline const char* get_units<std::mega>() {
+  return "Ms";
+}
+template <> FMT_CONSTEXPR inline const char* get_units<std::giga>() {
+  return "Gs";
+}
+template <> FMT_CONSTEXPR inline const char* get_units<std::tera>() {
+  return "Ts";
+}
+template <> FMT_CONSTEXPR inline const char* get_units<std::peta>() {
+  return "Ps";
+}
+template <> FMT_CONSTEXPR inline const char* get_units<std::exa>() {
+  return "Es";
+}
+template <> FMT_CONSTEXPR inline const char* get_units<std::ratio<60>>() {
   return "m";
 }
-template <> FMT_CONSTEXPR const char* get_units<std::ratio<3600>>() {
+template <> FMT_CONSTEXPR inline const char* get_units<std::ratio<3600>>() {
   return "h";
 }
 

include/fmt/color.h

@@ -353,16 +353,17 @@ class text_style {
 };
 
 /** Creates a text style from the foreground (text) color. */
-FMT_CONSTEXPR text_style fg(detail::color_type foreground) FMT_NOEXCEPT {
+FMT_CONSTEXPR inline text_style fg(detail::color_type foreground) FMT_NOEXCEPT {
   return text_style(true, foreground);
 }
 
 /** Creates a text style from the background color. */
-FMT_CONSTEXPR text_style bg(detail::color_type background) FMT_NOEXCEPT {
+FMT_CONSTEXPR inline text_style bg(detail::color_type background) FMT_NOEXCEPT {
   return text_style(false, background);
 }
 
-FMT_CONSTEXPR text_style operator|(emphasis lhs, emphasis rhs) FMT_NOEXCEPT {
+FMT_CONSTEXPR inline text_style operator|(emphasis lhs,
+                                          emphasis rhs) FMT_NOEXCEPT {
   return text_style(lhs) | rhs;
 }
 

include/fmt/core.h

@@ -92,7 +92,7 @@
 #  define FMT_CONSTEXPR constexpr
 #  define FMT_CONSTEXPR_DECL constexpr
 #else
-#  define FMT_CONSTEXPR inline
+#  define FMT_CONSTEXPR
 #  define FMT_CONSTEXPR_DECL
 #endif
 

include/fmt/format.h

@@ -287,7 +287,7 @@ namespace detail {
     (__cplusplus >= 201709L && FMT_GCC_VERSION >= 1002)
 #  define FMT_CONSTEXPR20 constexpr
 #else
-#  define FMT_CONSTEXPR20 inline
+#  define FMT_CONSTEXPR20
 #endif
 
 // An equivalent of `*reinterpret_cast<Dest*>(&source)` that doesn't have
@@ -984,7 +984,7 @@ template <typename T> FMT_CONSTEXPR int count_digits_fallback(T n) {
 #ifdef FMT_BUILTIN_CLZLL
 // Returns the number of decimal digits in n. Leading zeros are not counted
 // except for n == 0 in which case count_digits returns 1.
-FMT_CONSTEXPR20 int count_digits(uint64_t n) {
+FMT_CONSTEXPR20 inline int count_digits(uint64_t n) {
   if (is_constant_evaluated()) {
     return count_digits_fallback(n);
   }
@@ -994,11 +994,13 @@ FMT_CONSTEXPR20 int count_digits(uint64_t n) {
 }
 #else
 // Fallback version of count_digits used when __builtin_clz is not available.
-FMT_CONSTEXPR int count_digits(uint64_t n) { return count_digits_fallback(n); }
+FMT_CONSTEXPR inline int count_digits(uint64_t n) {
+  return count_digits_fallback(n);
+}
 #endif
 
 #if FMT_USE_INT128
-FMT_CONSTEXPR int count_digits(uint128_t n) {
+FMT_CONSTEXPR inline int count_digits(uint128_t n) {
   int count = 1;
   for (;;) {
     // Integer division is slow so do it for a group of four digits instead
@@ -1035,7 +1037,7 @@ template <> int count_digits<4>(detail::fallback_uintptr n);
 
 #ifdef FMT_BUILTIN_CLZ
 // Optional version of count_digits for better performance on 32-bit platforms.
-FMT_CONSTEXPR20 int count_digits(uint32_t n) {
+FMT_CONSTEXPR20 inline int count_digits(uint32_t n) {
   if (is_constant_evaluated()) {
     return count_digits_fallback(n);
   }
@@ -4034,11 +4036,11 @@ FMT_CONSTEXPR detail::udl_formatter<Char, CHARS...> operator""_format() {
     std::string message = "The answer is {}"_format(42);
   \endrst
  */
-FMT_CONSTEXPR detail::udl_formatter<char> operator"" _format(const char* s,
-                                                             size_t n) {
+FMT_CONSTEXPR inline detail::udl_formatter<char> operator"" _format(
+    const char* s, size_t n) {
   return {{s, n}};
 }
-FMT_CONSTEXPR detail::udl_formatter<wchar_t> operator"" _format(
+FMT_CONSTEXPR inline detail::udl_formatter<wchar_t> operator"" _format(
     const wchar_t* s, size_t n) {
   return {{s, n}};
 }
@@ -4054,10 +4056,12 @@ FMT_CONSTEXPR detail::udl_formatter<wchar_t> operator"" _format(
     fmt::print("Elapsed time: {s:.2f} seconds", "s"_a=1.23);
   \endrst
  */
-FMT_CONSTEXPR detail::udl_arg<char> operator"" _a(const char* s, size_t) {
+FMT_CONSTEXPR inline detail::udl_arg<char> operator"" _a(const char* s,
+                                                         size_t) {
   return {s};
 }
-FMT_CONSTEXPR detail::udl_arg<wchar_t> operator"" _a(const wchar_t* s, size_t) {
+FMT_CONSTEXPR inline detail::udl_arg<wchar_t> operator"" _a(const wchar_t* s,
+                                                            size_t) {
   return {s};
 }
 }  // namespace literals