1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
|
#include <util/generic/overloaded.h>
#include <library/cpp/testing/unittest/registar.h>
#include <util/generic/variant.h>
#include <util/generic/algorithm.h>
#include <tuple>
namespace {
struct TType1 {};
struct TType2 {};
struct TType3 {};
} // namespace
Y_UNIT_TEST_SUITE(TOverloadedTest) {
Y_UNIT_TEST(StaticTest) {
auto f = TOverloaded{
[](const TType1&) {},
[](const TType2&) {},
[](const TType3&) {}};
using F = decltype(f);
static_assert(std::is_invocable_v<F, TType1>);
static_assert(std::is_invocable_v<F, TType2>);
static_assert(std::is_invocable_v<F, TType3>);
static_assert(!std::is_invocable_v<F, int>);
static_assert(!std::is_invocable_v<F, double>);
}
Y_UNIT_TEST(VariantTest) {
std::variant<int, double, TType1> v = 5;
int res = 0;
std::visit(TOverloaded{
[&](int val) { res = val; },
[&](double) { res = -1; },
[&](TType1) { res = -1; }},
v);
UNIT_ASSERT_VALUES_EQUAL(res, 5);
}
Y_UNIT_TEST(TupleTest) {
std::tuple<int, double, bool, int> t{5, 3.14, true, 20};
TString res;
ForEach(t, TOverloaded{
[&](int val) { res += "(int) " + ToString(val) + ' '; },
[&](double val) { res += "(double) " + ToString(val) + ' '; },
[&](bool val) { res += "(bool) " + ToString(val) + ' '; },
});
UNIT_ASSERT_VALUES_EQUAL(res, "(int) 5 (double) 3.14 (bool) 1 (int) 20 ");
}
Y_UNIT_TEST(ImplicitConversionsTest) {
using TTestVariant = std::variant<int, double, char>;
// Purposefully exhibit inexact overload matched with implicit type
// conversions
// All cases implicitly cast to int
auto matchAsInt = [](TTestVariant var) {
return std::visit(TOverloaded{
[](int val) { return val; },
}, var);
};
UNIT_ASSERT_VALUES_EQUAL(matchAsInt(TTestVariant{17.77}), 17);
UNIT_ASSERT_VALUES_EQUAL(matchAsInt(TTestVariant{12345}), 12345);
UNIT_ASSERT_VALUES_EQUAL(matchAsInt(TTestVariant{'X'}), 88);
// All cases implicitly cast to double
auto matchAsDouble = [](TTestVariant var) {
return std::visit(TOverloaded{
[](double val) { return val; },
}, var);
};
UNIT_ASSERT_VALUES_EQUAL(matchAsDouble(TTestVariant{17.77}), 17.77);
UNIT_ASSERT_VALUES_EQUAL(matchAsDouble(TTestVariant{12345}), 12345.0);
UNIT_ASSERT_VALUES_EQUAL(matchAsDouble(TTestVariant{'X'}), 88.0);
}
} // Y_UNIT_TEST_SUITE(TOverloadedTest)
|
