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wip: modify from_json prototype

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Théo DELRIEU 2016-10-18 11:37:32 +02:00 committed by Théo DELRIEU
parent 63241db76e
commit f805dfcbbf
2 changed files with 94 additions and 3 deletions
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6
src/json.hpp
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@ -154,10 +154,10 @@ struct to_json_fn
struct from_json_fn
{
template <typename T>
constexpr auto operator()(T&& val) const -> decltype(from_json(std::forward<T>(val)))
template <typename Json, typename T>
constexpr auto operator()(Json const& from, T& to) const -> decltype(from_json(from, to))
{
return from_json(std::forward<T>(val));
return from_json(from, to);
}
};

91
test/src/unit-constructor3.cpp
View File

@ -58,6 +58,11 @@ public:
explicit operator bool() const noexcept { return _val != nullptr; }
T const &operator*() const { return *_val; }
optional_type& operator=(T const& t)
{
_val = std::make_shared<T>(t);
return *this;
}
private:
std::shared_ptr<T> _val;
@ -81,6 +86,33 @@ json to_json(bit_more_complex_type const& p)
return json{{"a", to_json(p.a)}, {"b", to_json(p.b)}, {"c", p.c}};
}
void from_json(json const&j, empty_type& t)
{
assert(j.empty());
t = empty_type{};
}
void from_json(json const&j, pod_type& t)
{
t = {j["a"].get<int>(), j["b"].get<char>(), j["c"].get<short>()};
}
void from_json(json const&j, bit_more_complex_type& t)
{
// relying on json_traits struct here..
t = {j["a"].get<udt::pod_type>(), j["b"].get<udt::pod_type>(),
j["c"].get<std::string>()};
}
template <typename T>
void from_json(json const& j, optional_type<T>& t)
{
if (j.is_null())
t = optional_type<T>{};
else
t = j.get<T>();
}
template <typename T>
json to_json(optional_type<T> const& opt)
{
@ -360,5 +392,64 @@ TEST_CASE("to_json free function", "[udt]")
auto const j = nlohmann::to_json(o);
CHECK(expected == j);
}
SECTION("from value")
{
udt::optional_type<udt::pod_type> o{{42, 42, 42}};
auto const expected = json{{"a", 42}, {"b", 42}, {"c", 42}};
auto const j = nlohmann::to_json(o);
CHECK(expected == j);
}
}
}
TEST_CASE("from_json free function", "[udt]")
{
SECTION("pod_type")
{
auto const expected = udt::pod_type{42, 42, 42};
auto const j = json{{"a", 42}, {"b", 42}, {"c", 42}};
// i really dislike this output parameter
udt::pod_type p;
nlohmann::from_json(j, p);
CHECK(p == expected);
}
SECTION("bit_more_complex_type")
{
auto const expected =
udt::bit_more_complex_type{{42, 42, 42}, {41, 41, 41}, "forty"};
auto const j = json{{"a", {{"a", 42}, {"b", 42}, {"c", 42}}},
{"b", {{"a", 41}, {"b", 41}, {"c", 41}}},
{"c", "forty"}};
udt::bit_more_complex_type p;
nlohmann::from_json(j, p);
CHECK(p == expected);
}
SECTION("optional_type")
{
SECTION("from null")
{
udt::optional_type<udt::pod_type> expected;
json j;
udt::optional_type<udt::pod_type> o;
nlohmann::from_json(j, o);
CHECK(expected == o);
}
SECTION("from value")
{
udt::optional_type<udt::pod_type> expected{{42, 42, 42}};
auto const j = json{{"a", 42}, {"b", 42}, {"c", 42}};
udt::optional_type<udt::pod_type> o;
nlohmann::from_json(j, o);
CHECK(expected == o);
}
}
}