Call parse on empty specs at compile time

fmtlib · Jul 16, 2023 · 661b23e · 661b23e
1 parent 8e87d3a
commit 661b23e
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Showing 3 changed files with 13 additions and 11 deletions.
diff --git a/include/fmt/core.h b/include/fmt/core.h
@@ -2627,7 +2627,9 @@ template <typename Char, typename... Args> class format_string_checker {
 #endif
   }
 
-  FMT_CONSTEXPR void on_replacement_field(int, const Char*) {}
+  FMT_CONSTEXPR void on_replacement_field(int id, const Char* begin) {
+    on_format_specs(id, begin, begin);  // Call parse() on empty specs.
+  }
 
   FMT_CONSTEXPR auto on_format_specs(int id, const Char* begin, const Char*)
       -> const Char* {

diff --git a/test/core-test.cc b/test/core-test.cc
@@ -273,7 +273,7 @@ struct custom_context {
   bool called = false;
 
   template <typename T> struct formatter_type {
-    auto parse(fmt::format_parse_context& ctx) -> decltype(ctx.begin()) {
+    FMT_CONSTEXPR auto parse(fmt::format_parse_context& ctx) -> decltype(ctx.begin()) {
       return ctx.begin();
     }
 
@@ -290,7 +290,7 @@ struct test_struct {};
 
 FMT_BEGIN_NAMESPACE
 template <typename Char> struct formatter<test_struct, Char> {
-  auto parse(format_parse_context& ctx) -> decltype(ctx.begin()) {
+  FMT_CONSTEXPR auto parse(format_parse_context& ctx) -> decltype(ctx.begin()) {
     return ctx.begin();
   }
 
@@ -573,7 +573,7 @@ struct disabled_formatter_convertible {
 
 FMT_BEGIN_NAMESPACE
 template <> struct formatter<enabled_formatter> {
-  auto parse(format_parse_context& ctx) -> decltype(ctx.begin()) {
+  FMT_CONSTEXPR auto parse(format_parse_context& ctx) -> decltype(ctx.begin()) {
     return ctx.begin();
   }
   auto format(enabled_formatter, format_context& ctx) const
@@ -583,7 +583,7 @@ template <> struct formatter<enabled_formatter> {
 };
 
 template <> struct formatter<enabled_ptr_formatter*> {
-  auto parse(format_parse_context& ctx) -> decltype(ctx.begin()) {
+  FMT_CONSTEXPR auto parse(format_parse_context& ctx) -> decltype(ctx.begin()) {
     return ctx.begin();
   }
   auto format(enabled_ptr_formatter*, format_context& ctx) const
@@ -607,7 +607,7 @@ struct nonconst_formattable {};
 
 FMT_BEGIN_NAMESPACE
 template <> struct formatter<const_formattable> {
-  auto parse(format_parse_context& ctx) -> decltype(ctx.begin()) {
+  FMT_CONSTEXPR auto parse(format_parse_context& ctx) -> decltype(ctx.begin()) {
     return ctx.begin();
   }
 
@@ -619,7 +619,7 @@ template <> struct formatter<const_formattable> {
 };
 
 template <> struct formatter<nonconst_formattable> {
-  auto parse(format_parse_context& ctx) -> decltype(ctx.begin()) {
+  FMT_CONSTEXPR auto parse(format_parse_context& ctx) -> decltype(ctx.begin()) {
     return ctx.begin();
   }
 
@@ -641,7 +641,7 @@ struct convertible_to_pointer_formattable {
 
 FMT_BEGIN_NAMESPACE
 template <> struct formatter<convertible_to_pointer_formattable> {
-  auto parse(format_parse_context& ctx) -> decltype(ctx.begin()) {
+  FMT_CONSTEXPR auto parse(format_parse_context& ctx) -> decltype(ctx.begin()) {
     return ctx.begin();
   }
 
@@ -721,7 +721,7 @@ struct convertible_to_cstring {
 
 FMT_BEGIN_NAMESPACE
 template <> struct formatter<convertible_to_int> {
-  auto parse(format_parse_context& ctx) -> decltype(ctx.begin()) {
+  FMT_CONSTEXPR auto parse(format_parse_context& ctx) -> decltype(ctx.begin()) {
     return ctx.begin();
   }
   auto format(convertible_to_int, format_context& ctx) const
@@ -842,7 +842,7 @@ struct its_a_trap {
 
 FMT_BEGIN_NAMESPACE
 template <> struct formatter<its_a_trap> {
-  auto parse(format_parse_context& ctx) -> decltype(ctx.begin()) {
+  FMT_CONSTEXPR auto parse(format_parse_context& ctx) -> decltype(ctx.begin()) {
     return ctx.begin();
   }
 

diff --git a/test/format-test.cc b/test/format-test.cc
@@ -2101,7 +2101,7 @@ struct check_back_appender {};
 
 FMT_BEGIN_NAMESPACE
 template <> struct formatter<check_back_appender> {
-  auto parse(format_parse_context& ctx) -> decltype(ctx.begin()) {
+  FMT_CONSTEXPR auto parse(format_parse_context& ctx) -> decltype(ctx.begin()) {
     return ctx.begin();
   }