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
|
//
// lager - library for functional interactive c++ programs
// Copyright (C) 2017 Juan Pedro Bolivar Puente
//
// This file is part of lager.
//
// lager is free software: you can redistribute it and/or modify
// it under the terms of the MIT License, as detailed in the LICENSE
// file located at the root of this source code distribution,
// or here: <https://github.com/arximboldi/lager/blob/master/LICENSE>
//
#include <catch2/catch.hpp>
#include <lager/util.hpp>
#include <variant>
using variant_t = std::variant<int, float, std::string>;
TEST_CASE("match")
{
auto v = variant_t{42};
auto y = lager::match(v)([](int x) { return x; }, [](auto) { return 0; });
CHECK(y == 42);
}
struct deriv_t : variant_t
{
using variant_t::variant_t;
};
TEST_CASE("match deriv")
{
auto v = deriv_t{42};
auto y = lager::match(v)([](int x) { return x; }, [](auto) { return 0; });
CHECK(y == 42);
}
// only literal types can be used in a constexpr
using literal_variant_t = std::variant<int, float, double>;
struct literal_deriv_t : literal_variant_t
{
using literal_variant_t::literal_variant_t;
};
TEST_CASE("match constexpr")
{
constexpr auto v = literal_variant_t{42};
constexpr auto y =
lager::match(v)([](int x) { return x; }, [](auto) { return 0; });
CHECK(y == 42);
}
TEST_CASE("match deriv constexpr ")
{
constexpr auto v = literal_deriv_t{42};
constexpr auto y =
lager::match(v)([](int x) { return x; }, [](auto) { return 0; });
CHECK(y == 42);
}
|
