GSL/tests/at_tests.cpp

///////////////////////////////////////////////////////////////////////////////
//
// Copyright (c) 2015 Microsoft Corporation. All rights reserved.
//
// This code is licensed under the MIT License (MIT).
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
//
///////////////////////////////////////////////////////////////////////////////

#include <UnitTest++/UnitTest++.h>
#include <gsl/gsl>
#include <vector>
#include <initializer_list>

using gsl::fail_fast;

SUITE(at_tests)
{
    TEST(static_array)
    {
        int a[4] = { 1, 2, 3, 4 };
        const int (&c_a)[4] = a;

        for (int i = 0; i < 4; ++i) {
            CHECK(&gsl::at(a, i) == &a[i]);
            CHECK(&gsl::at(c_a, i) == &a[i]);
        }

        CHECK_THROW(gsl::at(a, -1), fail_fast);
        CHECK_THROW(gsl::at(a, 4), fail_fast);
        CHECK_THROW(gsl::at(c_a, -1), fail_fast);
        CHECK_THROW(gsl::at(c_a, 4), fail_fast);
    }

    TEST(std_array)
    {
        std::array<int, 4> a = { 1, 2, 3, 4 };
        const std::array<int, 4>& c_a = a;

        for (int i = 0; i < 4; ++i) {
            CHECK(&gsl::at(a, i) == &a[i]);
            CHECK(&gsl::at(c_a, i) == &a[i]);
        }

        CHECK_THROW(gsl::at(a, -1), fail_fast);
        CHECK_THROW(gsl::at(a, 4), fail_fast);
        CHECK_THROW(gsl::at(c_a, -1), fail_fast);
        CHECK_THROW(gsl::at(c_a, 4), fail_fast);
    }

    TEST(StdVector)
    {
        std::vector<int> a = { 1, 2, 3, 4 };
        const std::vector<int>& c_a = a;

        for (int i = 0; i < 4; ++i) {
            CHECK(&gsl::at(a, i) == &a[i]);
            CHECK(&gsl::at(c_a, i) == &a[i]);
        }

        CHECK_THROW(gsl::at(a, -1), fail_fast);
        CHECK_THROW(gsl::at(a, 4), fail_fast);
        CHECK_THROW(gsl::at(c_a, -1), fail_fast);
        CHECK_THROW(gsl::at(c_a, 4), fail_fast);
    }

    TEST(InitializerList)
    {
        std::initializer_list<int> a = { 1, 2, 3, 4 };

        for (int i = 0; i < 4; ++i) {
            CHECK(gsl::at(a, i) == i+1);
            CHECK(gsl::at({1,2,3,4}, i) == i+1);
        }

        CHECK_THROW(gsl::at(a, -1), fail_fast);
        CHECK_THROW(gsl::at(a, 4), fail_fast);
        CHECK_THROW(gsl::at({1,2,3,4}, -1), fail_fast);
        CHECK_THROW(gsl::at({1,2,3,4}, 4), fail_fast);
    }
}

#if !defined(_MSC_VER) || (defined(__clang__) || _MSC_VER >= 1910)
static constexpr bool test_constexpr()
{
    int a1[4] = { 1, 2, 3, 4 };
    const int (&c_a1)[4] = a1;
    std::array<int,4> a2 = { 1, 2, 3, 4 };
    const std::array<int, 4>& c_a2 = a2;

    for (int i = 0; i < 4; ++i) {
        if (&gsl::at(a1, i) != &a1[i]) return false;
        if (&gsl::at(c_a1, i) != &a1[i]) return false;
        if (&gsl::at(c_a2, i) != &c_a2[i]) return false;
        if (gsl::at({1,2,3,4}, i) != i+1) return false;
    }

    return true;
}

static_assert(test_constexpr(), "FAIL");
#endif

int main()
{
    return UnitTest::RunAllTests();
}