1 #define CATCH_CONFIG_ENABLE_VARIANT_STRINGMAKER 2 #include "catch.hpp" 3 4 #if defined(CATCH_CONFIG_CPP17_VARIANT) && !defined(CATCH_CONFIG_DISABLE_EXCEPTIONS) 5 6 #include <string> 7 #include <variant> 8 9 // We need 2 types with non-trivial copies/moves 10 struct MyType1 { 11 MyType1() = default; MyType1MyType112 [[noreturn]] MyType1(MyType1 const&) { throw 1; } operator =MyType113 MyType1& operator=(MyType1 const&) { throw 3; } 14 }; 15 struct MyType2 { 16 MyType2() = default; MyType2MyType217 [[noreturn]] MyType2(MyType2 const&) { throw 2; } operator =MyType218 MyType2& operator=(MyType2 const&) { throw 4; } 19 }; 20 21 TEST_CASE( "variant<std::monostate>", "[toString][variant][approvals]") 22 { 23 using type = std::variant<std::monostate>; 24 CHECK( "{ }" == ::Catch::Detail::stringify(type{}) ); 25 type value {}; 26 CHECK( "{ }" == ::Catch::Detail::stringify(value) ); 27 CHECK( "{ }" == ::Catch::Detail::stringify(std::get<0>(value)) ); 28 } 29 30 TEST_CASE( "variant<int>", "[toString][variant][approvals]") 31 { 32 using type = std::variant<int>; 33 CHECK( "0" == ::Catch::Detail::stringify(type{0}) ); 34 } 35 36 TEST_CASE( "variant<float, int>", "[toString][variant][approvals]") 37 { 38 using type = std::variant<float, int>; 39 CHECK( "0.5f" == ::Catch::Detail::stringify(type{0.5f}) ); 40 CHECK( "0" == ::Catch::Detail::stringify(type{0}) ); 41 } 42 43 TEST_CASE( "variant -- valueless-by-exception", "[toString][variant][approvals]" ) { 44 using type = std::variant<MyType1, MyType2>; 45 46 type value; 47 REQUIRE_THROWS_AS(value.emplace<MyType2>(MyType2{}), int); 48 REQUIRE(value.valueless_by_exception()); 49 CHECK("{valueless variant}" == ::Catch::Detail::stringify(value)); 50 } 51 52 53 TEST_CASE( "variant<string, int>", "[toString][variant][approvals]") 54 { 55 using type = std::variant<std::string, int>; 56 CHECK( "\"foo\"" == ::Catch::Detail::stringify(type{"foo"}) ); 57 CHECK( "0" == ::Catch::Detail::stringify(type{0}) ); 58 } 59 60 TEST_CASE( "variant<variant<float, int>, string>", "[toString][variant][approvals]") 61 { 62 using inner = std::variant<MyType1, float, int>; 63 using type = std::variant<inner, std::string>; 64 CHECK( "0.5f" == ::Catch::Detail::stringify(type{0.5f}) ); 65 CHECK( "0" == ::Catch::Detail::stringify(type{0}) ); 66 CHECK( "\"foo\"" == ::Catch::Detail::stringify(type{"foo"}) ); 67 68 SECTION("valueless nested variant") { 69 type value = inner{0.5f}; 70 REQUIRE( std::holds_alternative<inner>(value) ); 71 REQUIRE( std::holds_alternative<float>(std::get<inner>(value)) ); 72 73 REQUIRE_THROWS_AS( std::get<0>(value).emplace<MyType1>(MyType1{}), int ); 74 75 // outer variant is still valid and contains inner 76 REQUIRE( std::holds_alternative<inner>(value) ); 77 // inner variant is valueless 78 REQUIRE( std::get<inner>(value).valueless_by_exception() ); 79 CHECK( "{valueless variant}" == ::Catch::Detail::stringify(value) ); 80 } 81 } 82 83 TEST_CASE( "variant<nullptr,int,const char *>", "[toString][variant][approvals]" ) 84 { 85 using type = std::variant<std::nullptr_t,int,const char *>; 86 CHECK( "nullptr" == ::Catch::Detail::stringify(type{nullptr}) ); 87 CHECK( "42" == ::Catch::Detail::stringify(type{42}) ); 88 CHECK( "\"Catch me\"" == ::Catch::Detail::stringify(type{"Catch me"}) ); 89 } 90 91 #endif // CATCH_INTERNAL_CONFIG_CPP17_VARIANT 92