Files
mp-units/test/unit_test/runtime/magnitude_test.cpp
T

503 lines
16 KiB
C++

// The MIT License (MIT)
//
// Copyright (c) 2018 Mateusz Pusz
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// 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 <units/magnitude.h>
#include <units/ratio.h>
#include <catch2/catch.hpp>
#include <type_traits>
namespace units {
// A set of non-standard bases for testing purposes.
struct noninteger_base { static constexpr long double value = 1.234L; };
struct noncanonical_two_base { static constexpr long double value = 2.0L; };
struct other_noncanonical_two_base { static constexpr long double value = 2.0L; };
struct invalid_zero_base { static constexpr long double value = 0.0L; };
struct invalid_negative_base { static constexpr long double value = -1.234L; };
template<ratio Power>
constexpr auto pi_to_the() { return magnitude<base_power<pi_base>{Power}>{}; }
template<typename T, typename U>
void check_same_type_and_value(T actual, U expected) {
CHECK(std::is_same_v<T, U>);
CHECK(actual == expected);
}
TEST_CASE("base_power")
{
SECTION("base rep deducible for integral base")
{
CHECK(base_power{2} == base_power<int>{2, ratio{1}});
CHECK(base_power{2, 3} == base_power<int>{2, ratio{3}});
CHECK(base_power{2, ratio{3, 4}} == base_power<int>{2, ratio{3, 4}});
}
SECTION("get_base retrieves base for integral base")
{
CHECK(base_power{2}.get_base() == 2);
CHECK(base_power{3, 5}.get_base() == 3);
CHECK(base_power{5, ratio{1, 3}}.get_base() == 5);
}
SECTION("get_base retrieves member value for non-integer base")
{
CHECK(base_power<noninteger_base>{}.get_base() == 1.234L);
CHECK(base_power<noninteger_base>{2}.get_base() == 1.234L);
CHECK(base_power<noninteger_base>{ratio{5, 8}}.get_base() == 1.234L);
}
SECTION("same-base values not equal if types are different")
{
const auto a = base_power<noncanonical_two_base>{};
const auto b = base_power{2};
const auto c = base_power<other_noncanonical_two_base>{};
REQUIRE(a.get_base() == b.get_base());
CHECK(a != b);
REQUIRE(a.get_base() == c.get_base());
CHECK(a != c);
}
SECTION("same-type values not equal if bases are different")
{
CHECK(base_power{2} != base_power{3});
CHECK(base_power{2, ratio{5, 4}} != base_power{3, ratio{5, 4}});
}
SECTION("same-type, same-base values not equal if powers are different")
{
CHECK(base_power{2} != base_power{2, 2});
CHECK(base_power<pi_base>{} != base_power<pi_base>{ratio{1, 3}});
}
SECTION("product with inverse equals identity")
{
auto check_product_with_inverse_is_identity = [] (auto x) {
CHECK(x * pow<-1>(x) == as_magnitude<1>());
};
check_product_with_inverse_is_identity(as_magnitude<3>());
check_product_with_inverse_is_identity(as_magnitude<ratio{4, 17}>());
check_product_with_inverse_is_identity(pi_to_the<ratio{-22, 7}>());
}
SECTION("pow() multiplies exponent")
{
CHECK(pow(base_power{2}, 0) == base_power{2, 0});
CHECK(pow(base_power{2, 3}, ratio{-1, 2}) == base_power{2, ratio{-3, 2}});
CHECK(pow(base_power<pi_base>{ratio{3, 2}}, ratio{1, 3}) == base_power<pi_base>{ratio{1, 2}});
}
}
TEST_CASE("make_ratio performs prime factorization correctly")
{
SECTION("Performs prime factorization when denominator is 1")
{
CHECK(as_magnitude<1>() == magnitude<>{});
CHECK(as_magnitude<2>() == magnitude<base_power{2}>{});
CHECK(as_magnitude<3>() == magnitude<base_power{3}>{});
CHECK(as_magnitude<4>() == magnitude<base_power{2, 2}>{});
CHECK(as_magnitude<792>() == magnitude<base_power{2, 3}, base_power{3, 2}, base_power{11}>{});
}
SECTION("Supports fractions")
{
CHECK(as_magnitude<ratio{5, 8}>() == magnitude<base_power{2, -3}, base_power{5}>{});
}
SECTION("Supports nonzero exp")
{
constexpr ratio r{3, 1, 2};
REQUIRE(r.exp == 2);
CHECK(as_magnitude<r>() == as_magnitude<300>());
}
}
TEST_CASE("magnitude converts to numerical value")
{
SECTION("Positive integer powers of integer bases give integer values")
{
constexpr auto mag_412 = as_magnitude<412>();
check_same_type_and_value(mag_412.value<int>, 412);
check_same_type_and_value(mag_412.value<std::size_t>, std::size_t{412});
check_same_type_and_value(mag_412.value<float>, 412.0f);
check_same_type_and_value(mag_412.value<double>, 412.0);
}
SECTION("Negative integer powers of integer bases compute correct values")
{
constexpr auto mag_0p125 = as_magnitude<ratio{1, 8}>();
check_same_type_and_value(mag_0p125.value<float>, 0.125f);
check_same_type_and_value(mag_0p125.value<double>, 0.125);
}
SECTION("pi to the 1 supplies correct values")
{
constexpr auto pi = pi_to_the<1>();
check_same_type_and_value(pi.value<float>, std::numbers::pi_v<float>);
check_same_type_and_value(pi.value<double>, std::numbers::pi_v<double>);
check_same_type_and_value(pi.value<long double>, std::numbers::pi_v<long double>);
}
SECTION("pi to arbitrary power performs computations in most accurate type at compile time")
{
if constexpr (sizeof(float) < sizeof(long double)) {
constexpr auto pi_cubed = pi_to_the<3>();
auto cube = [](auto x) { return x * x * x; };
constexpr auto via_float = cube(std::numbers::pi_v<float>);
constexpr auto via_long_double = static_cast<float>(cube(std::numbers::pi_v<long double>));
constexpr auto pi_cubed_value = pi_cubed.value<float>;
REQUIRE(pi_cubed_value != via_float);
CHECK(pi_cubed_value == via_long_double);
}
}
SECTION("Impossible requests are prevented at compile time")
{
// Naturally, we cannot actually write a test to verify a compiler error. But any of these can
// be uncommented if desired to verify that it breaks the build.
// (void)as_magnitude<412>().value<int8_t>;
// Would work for pow<62>:
// (void)pow<63>(as_magnitude<2>()).value<int64_t>;
// Would work for pow<63>:
// (void)pow<64>(as_magnitude<2>()).value<uint64_t>;
(void)pow<308>(as_magnitude<10>()).value<double>; // Compiles, correctly.
// (void)pow<309>(as_magnitude<10>()).value<double>;
// (void)pow<3099>(as_magnitude<10>()).value<double>;
// (void)pow<3099999>(as_magnitude<10>()).value<double>;
auto sqrt_2 = pow<ratio{1, 2}>(as_magnitude<2>());
CHECK(!is_integral(sqrt_2));
// (void)sqrt_2.value<int>;
}
}
TEST_CASE("Equality works for magnitudes")
{
SECTION("Equivalent ratios are equal")
{
CHECK(as_magnitude<1>() == as_magnitude<1>());
CHECK(as_magnitude<3>() == as_magnitude<3>());
CHECK(as_magnitude<ratio{3, 4}>() == as_magnitude<ratio{9, 12}>());
}
SECTION("Different ratios are unequal")
{
CHECK(as_magnitude<3>() != as_magnitude<5>());
CHECK(as_magnitude<3>() != as_magnitude<ratio{3, 2}>());
}
SECTION("Supports constexpr")
{
constexpr auto eq = (as_magnitude<ratio{4, 5}>() == as_magnitude<ratio{4, 3}>());
CHECK(!eq);
}
}
TEST_CASE("Multiplication works for magnitudes")
{
SECTION("Reciprocals reduce to null magnitude")
{
CHECK(as_magnitude<ratio{3, 4}>() * as_magnitude<ratio{4, 3}>() == as_magnitude<1>());
}
SECTION("Products work as expected")
{
CHECK(as_magnitude<ratio{4, 5}>() * as_magnitude<ratio{4, 3}>() == as_magnitude<ratio{16, 15}>());
}
SECTION("Products handle pi correctly")
{
CHECK(
pi_to_the<1>() * as_magnitude<ratio{2, 3}>() * pi_to_the<ratio{-1, 2}>() ==
magnitude<base_power{2}, base_power{3, -1}, base_power<pi_base>{ratio{1, 2}}>{});
}
SECTION("Supports constexpr")
{
constexpr auto p = as_magnitude<ratio{4, 5}>() * as_magnitude<ratio{4, 3}>();
CHECK(p == as_magnitude<ratio{16, 15}>());
}
}
TEST_CASE("Division works for magnitudes")
{
SECTION("Dividing anything by itself reduces to null magnitude")
{
CHECK(as_magnitude<ratio{3, 4}>() / as_magnitude<ratio{3, 4}>() == as_magnitude<1>());
CHECK(as_magnitude<15>() / as_magnitude<15>() == as_magnitude<1>());
}
SECTION("Quotients work as expected")
{
CHECK(as_magnitude<ratio{4, 5}>() / as_magnitude<ratio{4, 3}>() == as_magnitude<ratio{3, 5}>());
}
SECTION("Supports constexpr")
{
constexpr auto q = as_magnitude<ratio{4, 5}>() / as_magnitude<ratio{4, 3}>();
CHECK(q == as_magnitude<ratio{3, 5}>());
}
}
TEST_CASE("Can raise Magnitudes to rational powers")
{
SECTION("Anything to the 0 is 1") {
CHECK(pow<0>(as_magnitude<1>()) == as_magnitude<1>());
CHECK(pow<0>(as_magnitude<123>()) == as_magnitude<1>());
CHECK(pow<0>(as_magnitude<ratio{3, 4}>()) == as_magnitude<1>());
CHECK(pow<0>(pi_to_the<ratio{-1, 2}>()) == as_magnitude<1>());
}
SECTION("Anything to the 1 is itself") {
CHECK(pow<1>(as_magnitude<1>()) == as_magnitude<1>());
CHECK(pow<1>(as_magnitude<123>()) == as_magnitude<123>());
CHECK(pow<1>(as_magnitude<ratio{3, 4}>()) == as_magnitude<ratio{3, 4}>());
CHECK(pow<1>(pi_to_the<ratio{-1, 2}>()) == pi_to_the<ratio{-1, 2}>());
}
SECTION("Can raise to arbitrary rational power") {
CHECK(pow<ratio{-8, 3}>(pi_to_the<ratio{-1, 2}>()) == pi_to_the<ratio{4, 3}>());
}
}
TEST_CASE("can distinguish integral, rational, and irrational magnitudes")
{
SECTION("Integer magnitudes are integral and rational")
{
auto check_rational_and_integral = [](Magnitude auto m) {
CHECK(is_integral(m));
CHECK(is_rational(m));
};
check_rational_and_integral(magnitude<>{});
check_rational_and_integral(as_magnitude<1>());
check_rational_and_integral(as_magnitude<3>());
check_rational_and_integral(as_magnitude<8>());
check_rational_and_integral(as_magnitude<412>());
check_rational_and_integral(as_magnitude<ratio{1, 1}>());
}
SECTION("Fractional magnitudes are rational, but not integral")
{
auto check_rational_but_not_integral = [](Magnitude auto m) {
CHECK(!is_integral(m));
CHECK(is_rational(m));
};
check_rational_but_not_integral(as_magnitude<ratio{1, 2}>());
check_rational_but_not_integral(as_magnitude<ratio{5, 8}>());
}
}
namespace detail {
TEST_CASE("int_power computes integer powers") {
SECTION("handles floating point") {
check_same_type_and_value(int_power(0.123L, 0), 1.0L);
check_same_type_and_value(int_power(0.246f, 1), 0.246f);
check_same_type_and_value(int_power(0.5f, 3), 0.125f);
check_same_type_and_value(int_power(2.5, 4), 39.0625);
CHECK(std::is_same_v<long double, decltype(compute_base_power<double>(base_power{10, 20}))>);
}
SECTION("handles integral") {
check_same_type_and_value(int_power(8, 0), 1);
check_same_type_and_value(int_power(9L, 1), 9L);
check_same_type_and_value(int_power(2, 10), 1024);
}
}
TEST_CASE("Prime helper functions")
{
SECTION("find_first_factor()") {
CHECK(find_first_factor(1) == 1);
CHECK(find_first_factor(2) == 2);
CHECK(find_first_factor(4) == 2);
CHECK(find_first_factor(6) == 2);
CHECK(find_first_factor(15) == 3);
CHECK(find_first_factor(17) == 17);
}
SECTION("multiplicity") {
CHECK(multiplicity(2, 8) == 3);
CHECK(multiplicity(2, 1024) == 10);
CHECK(multiplicity(11, 6655) == 3);
}
SECTION("remove_power()") {
CHECK(remove_power(17, 0, 5) == 5);
CHECK(remove_power(2, 3, 24) == 3);
CHECK(remove_power(11, 3, 6655) == 5);
}
}
TEST_CASE("Prime factorization")
{
SECTION("1 factors into the null magnitude")
{
CHECK(prime_factorization_v<1> == magnitude<>{});
}
SECTION("Prime numbers factor into themselves")
{
CHECK(prime_factorization_v<2> == magnitude<base_power{2}>{});
CHECK(prime_factorization_v<3> == magnitude<base_power{3}>{});
CHECK(prime_factorization_v<5> == magnitude<base_power{5}>{});
CHECK(prime_factorization_v<7> == magnitude<base_power{7}>{});
CHECK(prime_factorization_v<11> == magnitude<base_power{11}>{});
CHECK(prime_factorization_v<41> == magnitude<base_power{41}>{});
}
SECTION("Prime factorization finds factors and multiplicities")
{
CHECK(prime_factorization_v<792> ==
magnitude<base_power{2, 3}, base_power{3, 2}, base_power{11}>{});
}
}
TEST_CASE("is_prime detects primes")
{
SECTION("Non-positive numbers are not prime")
{
CHECK(!is_prime(-1328));
CHECK(!is_prime(-1));
CHECK(!is_prime(0));
}
SECTION("1 is not prime")
{
CHECK(!is_prime(1));
}
SECTION("Discriminates between primes and non-primes")
{
CHECK(is_prime(2));
CHECK(is_prime(3));
CHECK(!is_prime(4));
CHECK(is_prime(5));
CHECK(!is_prime(6));
CHECK(is_prime(7));
CHECK(!is_prime(8));
CHECK(!is_prime(9));
CHECK(is_prime(7919));
}
}
TEST_CASE("is_valid_base_power")
{
SECTION("0 power is invalid") {
REQUIRE(is_valid_base_power(base_power{2}));
CHECK(!is_valid_base_power(base_power{2, 0}));
REQUIRE(is_valid_base_power(base_power{41}));
CHECK(!is_valid_base_power(base_power{41, 0}));
REQUIRE(is_valid_base_power(base_power<pi_base>{}));
CHECK(!is_valid_base_power(base_power<pi_base>{0}));
}
SECTION("non-prime integers are invalid") {
CHECK(!is_valid_base_power(base_power{-8}));
CHECK(!is_valid_base_power(base_power{0}));
CHECK(!is_valid_base_power(base_power{1}));
CHECK(is_valid_base_power(base_power{2}));
CHECK(is_valid_base_power(base_power{3}));
CHECK(!is_valid_base_power(base_power{4}));
}
SECTION("non-positive floating point bases are invalid") {
CHECK(!is_valid_base_power(base_power<invalid_zero_base>{}));
CHECK(!is_valid_base_power(base_power<invalid_negative_base>{}));
}
}
TEST_CASE("pairwise_all evaluates all pairs")
{
const auto all_pairs_return_true = pairwise_all{[](auto, auto){ return true; }};
const auto all_pairs_return_false = pairwise_all{[](auto, auto){ return false; }};
const auto all_increasing = pairwise_all{std::less{}};
SECTION("always true for empty tuples")
{
CHECK(all_pairs_return_true());
CHECK(all_pairs_return_false());
}
SECTION("always true for single-element tuples")
{
CHECK(all_pairs_return_true(1));
CHECK(all_pairs_return_false(3.14));
CHECK(all_pairs_return_true('x'));
}
SECTION("true for longer tuples iff true for all neighbouring pairs")
{
CHECK(all_increasing(1, 1.5));
CHECK(all_increasing(1, 1.5, 2));
CHECK(!all_increasing(1, 2.0, 2));
CHECK(!all_increasing(1, 2.5, 2));
CHECK(all_pairs_return_true('c', 1, 8.9, 42u));
CHECK(!all_pairs_return_false('c', 1, 8.9, 42u));
}
}
TEST_CASE("strictly_increasing")
{
SECTION("Empty input is sorted")
{
CHECK(strictly_increasing());
}
SECTION("Single-element input is sorted")
{
CHECK(strictly_increasing(3));
CHECK(strictly_increasing(15.42));
CHECK(strictly_increasing('c'));
}
SECTION("Multi-value inputs compare correctly")
{
CHECK(strictly_increasing(3, 3.14));
CHECK(!strictly_increasing(3, 3.0));
CHECK(!strictly_increasing(4, 3.0));
}
}
} // namespace detail
} // namespace units