Permalink
Browse files

Add StringMaker for std::variant, std::monostate (#1380)

The StringMaker is off by default and can be enabled by a new macro `CATCH_CONFIG_ENABLE_VARIANT_STRINGMAKER`, to avoid increasing the footprint of stringification machinery by default.
  • Loading branch information...
melak47 authored and horenmar committed Sep 20, 2018
1 parent a575536 commit c638c5720970f03033755dd9ebb0e4e6dccb1289
View
@@ -260,15 +260,15 @@ matrix:
addons:
apt:
sources: *all_sources
packages: ['clang-6.0', 'libstdc++-7-dev']
packages: ['clang-6.0', 'libstdc++-8-dev']
env: COMPILER='clang++-6.0' CPP17=1
- os: linux
compiler: clang
addons:
apt:
sources: *all_sources
packages: ['clang-6.0', 'libstdc++-7-dev']
packages: ['clang-6.0', 'libstdc++-8-dev']
env: COMPILER='clang++-6.0' CPP17=1 EXAMPLES=1 COVERAGE=1 EXTRAS=1
install:
View
@@ -128,6 +128,7 @@ Catch's selection, by defining either `CATCH_CONFIG_CPP11_TO_STRING` or
CATCH_CONFIG_CPP17_UNCAUGHT_EXCEPTIONS // Use std::uncaught_exceptions instead of std::uncaught_exception
CATCH_CONFIG_CPP17_STRING_VIEW // Provide StringMaker specialization for std::string_view
CATCH_CONFIG_CPP17_VARIANT // Override C++17 detection for CATCH_CONFIG_ENABLE_VARIANT_STRINGMAKER
Catch contains basic compiler/standard detection and attempts to use
some C++17 features whenever appropriate. This automatic detection
@@ -202,6 +203,7 @@ By default, Catch does not stringify some types from the standard library. This
CATCH_CONFIG_ENABLE_PAIR_STRINGMAKER // Provide StringMaker specialization for std::pair
CATCH_CONFIG_ENABLE_TUPLE_STRINGMAKER // Provide StringMaker specialization for std::tuple
CATCH_CONFIG_ENABLE_CHRONO_STRINGMAKER // Provide StringMaker specialization for std::chrono::duration, std::chrono::timepoint
CATCH_CONFIG_ENABLE_VARIANT_STRINGMAKER // Provide StringMaker specialization for std::variant, std::monostate (on C++17)
CATCH_CONFIG_ENABLE_ALL_STRINGMAKERS // Defines all of the above
@@ -163,6 +163,23 @@
#endif
#endif
////////////////////////////////////////////////////////////////////////////////
// Check if variant is available and usable
#if defined(__has_include)
# if __has_include(<variant>) && defined(CATCH_CPP17_OR_GREATER)
# if defined(__clang__) && (__clang_major__ < 8)
// work around clang bug with libstdc++ https://bugs.llvm.org/show_bug.cgi?id=31852
// fix should be in clang 8, workaround in libstdc++ 8.2
# include <ciso646>
# if defined(__GLIBCXX__) && defined(_GLIBCXX_RELEASE) && (_GLIBCXX_RELEASE < 9)
# define CATCH_CONFIG_NO_CPP17_VARIANT
# else
# define CATCH_INTERNAL_CONFIG_CPP17_VARIANT
# endif // defined(__GLIBCXX__) && defined(_GLIBCXX_RELEASE) && (_GLIBCXX_RELEASE < 9)
# endif // defined(__clang__) && (__clang_major__ < 8)
# endif // __has_include(<variant>) && defined(CATCH_CPP17_OR_GREATER)
#endif // __has_include
#if defined(CATCH_INTERNAL_CONFIG_COUNTER) && !defined(CATCH_CONFIG_NO_COUNTER) && !defined(CATCH_CONFIG_COUNTER)
# define CATCH_CONFIG_COUNTER
@@ -191,6 +208,10 @@
# define CATCH_CONFIG_CPP17_STRING_VIEW
#endif
#if defined(CATCH_INTERNAL_CONFIG_CPP17_VARIANT) && !defined(CATCH_CONFIG_NO_CPP17_VARIANT) && !defined(CATCH_CONFIG_CPP17_VARIANT)
# define CATCH_CONFIG_CPP17_VARIANT
#endif
#if defined(CATCH_CONFIG_EXPERIMENTAL_REDIRECT)
# define CATCH_INTERNAL_CONFIG_NEW_CAPTURE
#endif
@@ -354,6 +354,7 @@ namespace Catch {
#if defined(CATCH_CONFIG_ENABLE_ALL_STRINGMAKERS)
# define CATCH_CONFIG_ENABLE_PAIR_STRINGMAKER
# define CATCH_CONFIG_ENABLE_TUPLE_STRINGMAKER
# define CATCH_CONFIG_ENABLE_VARIANT_STRINGMAKER
# define CATCH_CONFIG_ENABLE_CHRONO_STRINGMAKER
#endif
@@ -418,6 +419,34 @@ namespace Catch {
}
#endif // CATCH_CONFIG_ENABLE_TUPLE_STRINGMAKER
#if defined(CATCH_CONFIG_ENABLE_VARIANT_STRINGMAKER) && defined(CATCH_CONFIG_CPP17_VARIANT)
#include <variant>
namespace Catch {
template<>
struct StringMaker<std::monostate> {
static std::string convert(const std::monostate&) {
return "{ }";
}
};
template<typename... Elements>
struct StringMaker<std::variant<Elements...>> {
static std::string convert(const std::variant<Elements...>& variant) {
if (variant.valueless_by_exception()) {
return "{valueless variant}";
} else {
return std::visit(
[](const auto& value) {
return ::Catch::Detail::stringify(value);
},
variant
);
}
}
};
}
#endif // CATCH_CONFIG_ENABLE_VARIANT_STRINGMAKER
namespace Catch {
struct not_this_one {}; // Tag type for detecting which begin/ end are being selected
View
@@ -38,6 +38,7 @@ set(TEST_SOURCES
${SELF_TEST_DIR}/UsageTests/ToStringGeneral.tests.cpp
${SELF_TEST_DIR}/UsageTests/ToStringPair.tests.cpp
${SELF_TEST_DIR}/UsageTests/ToStringTuple.tests.cpp
${SELF_TEST_DIR}/UsageTests/ToStringVariant.tests.cpp
${SELF_TEST_DIR}/UsageTests/ToStringVector.tests.cpp
${SELF_TEST_DIR}/UsageTests/ToStringWhich.tests.cpp
${SELF_TEST_DIR}/UsageTests/Tricky.tests.cpp
@@ -0,0 +1,84 @@
#define CATCH_CONFIG_ENABLE_VARIANT_STRINGMAKER
#include "catch.hpp"
#if defined(CATCH_CONFIG_CPP17_VARIANT)
#include <string>
#include <variant>
TEST_CASE( "variant<std::monostate>", "[toString][variant][approvals]")
{
using type = std::variant<std::monostate>;
CHECK( "{ }" == ::Catch::Detail::stringify(type{}) );
type value {};
CHECK( "{ }" == ::Catch::Detail::stringify(value) );
CHECK( "{ }" == ::Catch::Detail::stringify(std::get<0>(value)) );
}
TEST_CASE( "variant<int>", "[toString][variant][approvals]")
{
using type = std::variant<int>;
CHECK( "0" == ::Catch::Detail::stringify(type{0}) );
}
TEST_CASE( "variant<float, int>", "[toString][variant][approvals]")
{
using type = std::variant<float, int>;
CHECK( "0.5f" == ::Catch::Detail::stringify(type{0.5f}) );
CHECK( "0" == ::Catch::Detail::stringify(type{0}) );
SECTION("valueless by exception") {
struct sample {
operator int() const { throw 42; }
};
type value{1.5f};
REQUIRE_THROWS_AS( value.emplace<int>(sample{}), int );
REQUIRE( value.valueless_by_exception() );
CHECK( "{valueless variant}" == ::Catch::Detail::stringify(value) );
}
}
TEST_CASE( "variant<string, int>", "[toString][variant][approvals]")
{
using type = std::variant<std::string, int>;
CHECK( "\"foo\"" == ::Catch::Detail::stringify(type{"foo"}) );
CHECK( "0" == ::Catch::Detail::stringify(type{0}) );
}
TEST_CASE( "variant<variant<float, int>, string>", "[toString][variant][approvals]")
{
using inner = std::variant<float, int>;
using type = std::variant<inner, std::string>;
CHECK( "0.5f" == ::Catch::Detail::stringify(type{0.5f}) );
CHECK( "0" == ::Catch::Detail::stringify(type{0}) );
CHECK( "\"foo\"" == ::Catch::Detail::stringify(type{"foo"}) );
struct sample {
operator int() const { throw 42; }
};
SECTION("valueless nested variant") {
type value = inner{0.5f};
REQUIRE( std::holds_alternative<inner>(value) );
REQUIRE( std::holds_alternative<float>(std::get<inner>(value)) );
REQUIRE_THROWS_AS( std::get<0>(value).emplace<int>(sample{}), int );
// outer variant is still valid and contains inner
REQUIRE( std::holds_alternative<inner>(value) );
// inner variant is valueless
REQUIRE( std::get<inner>(value).valueless_by_exception() );
CHECK( "{valueless variant}" == ::Catch::Detail::stringify(value) );
}
}
TEST_CASE( "variant<nullptr,int,const char *>", "[toString][variant][approvals]" )
{
using type = std::variant<std::nullptr_t,int,const char *>;
CHECK( "nullptr" == ::Catch::Detail::stringify(type{nullptr}) );
CHECK( "42" == ::Catch::Detail::stringify(type{42}) );
CHECK( "\"Catch me\"" == ::Catch::Detail::stringify(type{"Catch me"}) );
}
#endif // CATCH_INTERNAL_CONFIG_CPP17_VARIANT

0 comments on commit c638c57

Please sign in to comment.