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Niels Lohmann 2021-03-23 22:31:19 +01:00 committed by GitHub
commit 04f4c54090
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5 changed files with 129 additions and 0 deletions

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@ -32,6 +32,21 @@ void from_json(const BasicJsonType& j, typename std::nullptr_t& n)
n = nullptr;
}
#ifdef JSON_HAS_CPP_17
template<typename BasicJsonType, typename T>
void from_json(const BasicJsonType& j, std::optional<T>& opt)
{
if (j.is_null())
{
opt = std::nullopt;
}
else
{
opt = j.template get<T>();
}
}
#endif
// overloads for basic_json template parameters
template < typename BasicJsonType, typename ArithmeticType,
enable_if_t < std::is_arithmetic<ArithmeticType>::value&&

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@ -227,6 +227,22 @@ struct external_constructor<value_t::object>
// to_json //
/////////////
#ifdef JSON_HAS_CPP_17
template<typename BasicJsonType, typename T,
enable_if_t<std::is_constructible<BasicJsonType, T>::value, int> = 0>
void to_json(BasicJsonType& j, const std::optional<T>& opt)
{
if (opt.has_value())
{
j = *opt;
}
else
{
j = nullptr;
}
}
#endif
template<typename BasicJsonType, typename T,
enable_if_t<std::is_same<T, typename BasicJsonType::boolean_t>::value, int> = 0>
void to_json(BasicJsonType& j, T b) noexcept

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@ -31,6 +31,10 @@
#define JSON_HAS_CPP_14
#endif
#ifdef JSON_HAS_CPP_17
#include <optional>
#endif
// disable float-equal warnings on GCC/clang
#if defined(__clang__) || defined(__GNUC__) || defined(__GNUG__)
#pragma GCC diagnostic push

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@ -2237,6 +2237,10 @@ JSON_HEDLEY_DIAGNOSTIC_POP
#define JSON_HAS_CPP_14
#endif
#ifdef JSON_HAS_CPP_17
#include <optional>
#endif
// disable float-equal warnings on GCC/clang
#if defined(__clang__) || defined(__GNUC__) || defined(__GNUG__)
#pragma GCC diagnostic push
@ -3717,6 +3721,21 @@ void from_json(const BasicJsonType& j, typename std::nullptr_t& n)
n = nullptr;
}
#ifdef JSON_HAS_CPP_17
template<typename BasicJsonType, typename T>
void from_json(const BasicJsonType& j, std::optional<T>& opt)
{
if (j.is_null())
{
opt = std::nullopt;
}
else
{
opt = j.template get<T>();
}
}
#endif
// overloads for basic_json template parameters
template < typename BasicJsonType, typename ArithmeticType,
enable_if_t < std::is_arithmetic<ArithmeticType>::value&&
@ -4500,6 +4519,22 @@ struct external_constructor<value_t::object>
// to_json //
/////////////
#ifdef JSON_HAS_CPP_17
template<typename BasicJsonType, typename T,
enable_if_t<std::is_constructible<BasicJsonType, T>::value, int> = 0>
void to_json(BasicJsonType& j, const std::optional<T>& opt)
{
if (opt.has_value())
{
j = *opt;
}
else
{
j = nullptr;
}
}
#endif
template<typename BasicJsonType, typename T,
enable_if_t<std::is_same<T, typename BasicJsonType::boolean_t>::value, int> = 0>
void to_json(BasicJsonType& j, T b) noexcept

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@ -1703,6 +1703,65 @@ TEST_CASE("JSON to enum mapping")
}
}
#ifdef JSON_HAS_CPP_17
TEST_CASE("std::optional")
{
SECTION("null")
{
json j_null;
std::optional<std::string> opt_null;
CHECK(json(opt_null) == j_null);
CHECK(std::optional<std::string>(j_null) == std::nullopt);
}
SECTION("string")
{
json j_string = "string";
std::optional<std::string> opt_string = "string";
CHECK(json(opt_string) == j_string);
CHECK(std::optional<std::string>(j_string) == opt_string);
}
SECTION("bool")
{
json j_bool = true;
std::optional<bool> opt_bool = true;
CHECK(json(opt_bool) == j_bool);
CHECK(std::optional<bool>(j_bool) == opt_bool);
}
SECTION("number")
{
json j_number = 1;
std::optional<int> opt_int = 1;
CHECK(json(opt_int) == j_number);
CHECK(std::optional<int>(j_number) == opt_int);
}
SECTION("array")
{
json j_array = {1, 2, nullptr};
std::vector<std::optional<int>> opt_array = {{1, 2, std::nullopt}};
CHECK(json(opt_array) == j_array);
CHECK(std::vector<std::optional<int>>(j_array) == opt_array);
}
SECTION("object")
{
json j_object = {{"one", 1}, {"two", 2}, {"zero", nullptr}};
std::map<std::string, std::optional<int>> opt_object {{"one", 1}, {"two", 2}, {"zero", std::nullopt}};
CHECK(json(opt_object) == j_object);
CHECK(std::map<std::string, std::optional<int>>(j_object) == opt_object);
}
}
#endif
#ifdef JSON_HAS_CPP_17
#undef JSON_HAS_CPP_17
#endif