Fix regex-disabled builds

eliaskosunen · Jan 17, 2024 · 5bf72ea · 5bf72ea
1 parent ffd2a13
commit 5bf72ea
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Showing 3 changed files with 46 additions and 16 deletions.
diff --git a/include/scn/detail/args.h b/include/scn/detail/args.h
@@ -124,6 +124,8 @@ struct unscannable {};
 struct unscannable_char : unscannable {};
 struct unscannable_const : unscannable {};
 struct unscannable_disabled : unscannable {
+    unscannable_disabled() = default;
+
     template <typename T>
     constexpr unscannable_disabled(T&&)
     {
@@ -237,8 +239,6 @@ struct arg_mapper {
     SCN_ARG_MAPPER(std::string)
     SCN_ARG_MAPPER(std::wstring)
 
-    SCN_ARG_MAPPER(basic_regex_matches<char_type>)
-
 #undef SCN_ARG_MAPPER
 
     static decltype(auto) map(char& val)
@@ -256,6 +256,16 @@ struct arg_mapper {
         }
     }
 
+    static decltype(auto) map(basic_regex_matches<char_type>& val)
+    {
+        if constexpr (is_type_disabled<char_type>) {
+            return unscannable_disabled{val};
+        }
+        else {
+            return val;
+        }
+    }
+
     static unscannable_char map(std::basic_string_view<other_char_type>&)
     {
         return {};

diff --git a/src/scn/impl/reader/regex_reader.h b/src/scn/impl/reader/regex_reader.h
@@ -39,6 +39,15 @@ namespace scn {
 SCN_BEGIN_NAMESPACE
 
 namespace impl {
+
+// Forward declaration for C++17 compatibility with regex disabled
+template <typename CharT, typename Input>
+auto read_regex_matches_impl(std::basic_string_view<CharT> pattern,
+                             detail::regex_flags flags,
+                             Input input,
+                             basic_regex_matches<CharT>& value)
+    -> scan_expected<ranges::iterator_t<Input>>;
+
 #if !SCN_DISABLE_REGEX
 
 #if SCN_REGEX_BACKEND == SCN_REGEX_BACKEND_STD
@@ -411,8 +420,6 @@ auto read_regex_matches_impl(std::basic_string_view<CharT> pattern,
 #endif  // SCN_REGEX_BACKEND == ...
 }
 
-#endif  // !SCN_DISABLE_REGEX
-
 inline std::string get_unescaped_regex_pattern(std::string_view pattern)
 {
     std::string result{pattern};
@@ -432,6 +439,8 @@ inline std::wstring get_unescaped_regex_pattern(std::wstring_view pattern)
     return result;
 }
 
+#endif  // !SCN_DISABLE_REGEX
+
 template <typename SourceCharT>
 struct regex_matches_reader
     : public reader_base<regex_matches_reader<SourceCharT>, SourceCharT> {
@@ -497,11 +506,18 @@ struct regex_matches_reader
               detail::regex_flags flags,
               basic_regex_matches<DestCharT>& value)
     {
-        if (is_escaped) {
-            return read_regex_matches_impl<SourceCharT>(
-                get_unescaped_regex_pattern(pattern), flags, input, value);
+        if constexpr (detail::is_type_disabled<
+                          basic_regex_matches<DestCharT>>) {
+            SCN_EXPECT(false);
+            SCN_UNREACHABLE;
+        }
+        else {
+            if (is_escaped) {
+                return read_regex_matches_impl<SourceCharT>(
+                    get_unescaped_regex_pattern(pattern), flags, input, value);
+            }
+            return read_regex_matches_impl(pattern, flags, input, value);
         }
-        return read_regex_matches_impl(pattern, flags, input, value);
     }
 };
 

diff --git a/tests/unittests/compilefail_tests/CMakeLists.txt b/tests/unittests/compilefail_tests/CMakeLists.txt
@@ -12,18 +12,22 @@ set(buildfail_sources
         locale_flag_with_string.cpp
         negative_argument_id.cpp
         regex_disabled.cpp
-        regex_empty.cpp
-        regex_flag_invalid.cpp
-        regex_flag_multiple.cpp
-        regex_matches_non_contiguous_source.cpp
-        regex_no_presentation.cpp
-        regex_non_contiguous_source.cpp
-        regex_unterminated.cpp
-        regex_wide_strings.cpp
         string_view_non_contiguous_source.cpp
         unterminated_argument_id.cpp
         unterminated_format_specifier.cpp
 )
+if (NOT SCN_DISABLE_REGEX)
+    list(APPEND buildfail_sources
+            regex_empty.cpp
+            regex_flag_invalid.cpp
+            regex_flag_multiple.cpp
+            regex_matches_non_contiguous_source.cpp
+            regex_no_presentation.cpp
+            regex_non_contiguous_source.cpp
+            regex_unterminated.cpp
+            regex_wide_strings.cpp
+    )
+endif ()
 
 if (SCN_CXX_FRONTEND STREQUAL "GNU" OR SCN_CXX_FRONTEND STREQUAL "Clang")
     icm_add_multiple_build_failure_tests(