<format>: compile time checks (#2221)

Co-authored-by: Michael Schellenberger Costa <mschellenbergercosta@gmail.com> Co-authored-by: Stephan T. Lavavej <stl@microsoft.com>
microsoft · Dec 17, 2021 · 9265c51 · 9265c51
1 parent 568a21b
commit 9265c51
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Showing 12 changed files with 443 additions and 217 deletions.
diff --git a/stl/inc/chrono b/stl/inc/chrono
@@ -5829,11 +5829,11 @@ namespace chrono {
     struct _Chrono_formatter {
         _Chrono_formatter() = default;
 
-        explicit _Chrono_formatter(const basic_string_view<_CharT> _Time_zone_abbreviation_)
+        constexpr explicit _Chrono_formatter(const basic_string_view<_CharT> _Time_zone_abbreviation_)
             : _Time_zone_abbreviation{_Time_zone_abbreviation_} {}
 
         template <class _Ty>
-        _NODISCARD auto _Parse(basic_format_parse_context<_CharT>& _Parse_ctx) {
+        _NODISCARD constexpr auto _Parse(basic_format_parse_context<_CharT>& _Parse_ctx) {
             _Chrono_specs_setter<_CharT, basic_format_parse_context<_CharT>> _Callback{_Specs, _Parse_ctx};
             const auto _It =
                 _Parse_chrono_format_specs(_Parse_ctx._Unchecked_begin(), _Parse_ctx._Unchecked_end(), _Callback);
@@ -5867,39 +5867,39 @@ namespace chrono {
             return _Res_iter;
         }
 
-        static void _Check_modifier(const char _Type, const char _Modifier) {
-            if (_Modifier == '\0') {
-                return;
-            }
+        enum _Allowed_bit : uint8_t { _E_mod = 1, _O_mod = 2, _EO_mod = _E_mod | _O_mod };
 
-            enum _Allowed_bit : uint8_t { _E_mod = 1, _O_mod = 2, _EO_mod = _E_mod | _O_mod };
+        struct _Table_entry {
+            char _Type;
+            _Allowed_bit _Allowed;
+        };
 
-            struct _Table_entry {
-                char _Type;
-                _Allowed_bit _Allowed;
-            };
+        static constexpr _Table_entry _Table[] = {
+            {'c', _E_mod},
+            {'C', _E_mod},
+            {'d', _O_mod},
+            {'e', _O_mod},
+            {'H', _O_mod},
+            {'I', _O_mod},
+            {'m', _O_mod},
+            {'M', _O_mod},
+            {'S', _O_mod},
+            {'u', _O_mod},
+            {'U', _O_mod},
+            {'V', _O_mod},
+            {'w', _O_mod},
+            {'W', _O_mod},
+            {'x', _E_mod},
+            {'X', _E_mod},
+            {'y', _EO_mod},
+            {'Y', _E_mod},
+            {'z', _EO_mod},
+        };
 
-            static constexpr _Table_entry _Table[] = {
-                {'c', _E_mod},
-                {'C', _E_mod},
-                {'d', _O_mod},
-                {'e', _O_mod},
-                {'H', _O_mod},
-                {'I', _O_mod},
-                {'m', _O_mod},
-                {'M', _O_mod},
-                {'S', _O_mod},
-                {'u', _O_mod},
-                {'U', _O_mod},
-                {'V', _O_mod},
-                {'w', _O_mod},
-                {'W', _O_mod},
-                {'x', _E_mod},
-                {'X', _E_mod},
-                {'y', _EO_mod},
-                {'Y', _E_mod},
-                {'z', _EO_mod},
-            };
+        static constexpr void _Check_modifier(const char _Type, const char _Modifier) {
+            if (_Modifier == '\0') {
+                return;
+            }
 
             const _Allowed_bit _Mod = _Modifier == 'E' ? _E_mod : _O_mod;
 
@@ -6329,7 +6329,7 @@ namespace chrono {
 
 template <class _Ty, class _CharT>
 struct _Fill_tm_formatter {
-    auto parse(basic_format_parse_context<_CharT>& _Parse_ctx) {
+    constexpr auto parse(basic_format_parse_context<_CharT>& _Parse_ctx) {
         return _Impl.template _Parse<_Ty>(_Parse_ctx);
     }
 
@@ -6420,7 +6420,7 @@ struct formatter<_CHRONO local_info, _CharT> //
 
 template <class _Duration, class _CharT>
 struct formatter<_CHRONO sys_time<_Duration>, _CharT> {
-    auto parse(basic_format_parse_context<_CharT>& _Parse_ctx) {
+    constexpr auto parse(basic_format_parse_context<_CharT>& _Parse_ctx) {
         return _Impl.template _Parse<_CHRONO sys_time<_Duration>>(_Parse_ctx);
     }
 
@@ -6435,7 +6435,7 @@ private:
 
 template <class _Duration, class _CharT>
 struct formatter<_CHRONO utc_time<_Duration>, _CharT> {
-    auto parse(basic_format_parse_context<_CharT>& _Parse_ctx) {
+    constexpr auto parse(basic_format_parse_context<_CharT>& _Parse_ctx) {
         return _Impl.template _Parse<_CHRONO utc_time<_Duration>>(_Parse_ctx);
     }
 
@@ -6451,7 +6451,7 @@ private:
 
 template <class _Duration, class _CharT>
 struct formatter<_CHRONO tai_time<_Duration>, _CharT> {
-    auto parse(basic_format_parse_context<_CharT>& _Parse_ctx) {
+    constexpr auto parse(basic_format_parse_context<_CharT>& _Parse_ctx) {
         return _Impl.template _Parse<_CHRONO tai_time<_Duration>>(_Parse_ctx);
     }
 
@@ -6470,7 +6470,7 @@ private:
 
 template <class _Duration, class _CharT>
 struct formatter<_CHRONO gps_time<_Duration>, _CharT> {
-    auto parse(basic_format_parse_context<_CharT>& _Parse_ctx) {
+    constexpr auto parse(basic_format_parse_context<_CharT>& _Parse_ctx) {
         return _Impl.template _Parse<_CHRONO gps_time<_Duration>>(_Parse_ctx);
     }
 
@@ -6489,7 +6489,7 @@ private:
 
 template <class _Duration, class _CharT>
 struct formatter<_CHRONO file_time<_Duration>, _CharT> {
-    auto parse(basic_format_parse_context<_CharT>& _Parse_ctx) {
+    constexpr auto parse(basic_format_parse_context<_CharT>& _Parse_ctx) {
         return _Impl.template _Parse<_CHRONO file_time<_Duration>>(_Parse_ctx);
     }