ISSUE-48 : added verify_enum

README.md

@@ -78,6 +78,14 @@ enum flub { blub, glub };
 static_assert(!wise_enum::is_wise_enum_v<flub>, "");
 ```
 
+Check if a value defined as valid enumerator:
+
+
+```cpp
+static_assert(wise_enum::verify_enum(my_lib::Color::RED));
+static_assert(!wise_enum::verify_enum(static_cast<my_lib::Color>(10)));
+```
+
 ### Design
 
 It has a few notable design choices.

examples/example.x.cpp

@@ -75,5 +75,8 @@ int main() {
   o.reset();
   assert(!o);
 
+  static_assert(wise_enum::verify_enum(my_lib::Color::RED));
+  static_assert(!wise_enum::verify_enum(static_cast<my_lib::Color>(10)));
+
   return 0;
 }

wise_enum.h

@@ -53,6 +53,12 @@ constexpr string_type to_string(T t) {
   return wise_enum_detail_to_string(t, detail::Tag<T>{});
 }
 
+// returns if enumerator is valid enumerator value
+template <class T>
+constexpr bool verify_enum(T t) {
+  return wise_enum_detail_verify(t, detail::Tag<T>{});
+}
+
 // Enumerators trait class. Each value is also available as a template variable
 // for C++14 and on
 template <class T>

wise_enum_detail.h

@@ -154,6 +154,10 @@ WISE_ENUM_CONSTEXPR_14 bool compare(U u1, U u2) {
   case name::WISE_ENUM_IMPL_ONLY_OR_FIRST(x):                                  \
     return WISE_ENUM_IMPL_ENUM_STR(x);
 
+#define WISE_ENUM_IMPL_VERIFY_CASE(name, x)                                    \
+  case name::WISE_ENUM_IMPL_ONLY_OR_FIRST(x):                                  \
+    return true;
+
 #define WISE_ENUM_IMPL_STORAGE_2(x, y) y
 
 #define WISE_ENUM_IMPL_STORAGE(x)                                              \
@@ -205,4 +209,15 @@ WISE_ENUM_CONSTEXPR_14 bool compare(U u1, U u2) {
            WISE_ENUM_IMPL_NOTHING, __VA_ARGS__))                               \
     }                                                                          \
     return {};                                                                 \
+  }                                                                            \
+  template <class T>                                                           \
+  friendly WISE_ENUM_CONSTEXPR_14 bool                                         \
+  wise_enum_detail_verify(T e, ::wise_enum::detail::Tag<name>) {               \
+    switch (e) {                                                               \
+      WISE_ENUM_IMPL_EXPAND(loop(WISE_ENUM_IMPL_VERIFY_CASE, name,             \
+           WISE_ENUM_IMPL_NOTHING, __VA_ARGS__))                               \
+    }                                                                          \
+    return false;                                                              \
   }
+
+