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Turn get_value into free function

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This commit is contained in:
Chip Hogg
2022-01-29 02:40:51 +00:00
parent d6eb25f07a
commit b36bc2b582
2 changed files with 27 additions and 24 deletions
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15
src/core/include/units/magnitude.h
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@@ -336,14 +336,9 @@ struct magnitude {
// The value of this magnitude, expressed in a given type.
template<typename T>
requires (std::is_floating_point_v<T> || (detail::is_integral(BPs) && ...))
requires (std::is_floating_point_v<T> || (std::is_integral_v<T> && is_magnitude_integral))
static constexpr T value = detail::checked_static_cast<T>(
(detail::compute_base_power<T>(BPs) * ...));
// Trying to satisfy MSVC 14...
template<typename T>
requires (std::is_floating_point_v<T> || (detail::is_integral(BPs) && ...))
constexpr T get_value() const { return magnitude::value<T>; }
};
// Implementation for Magnitude concept (below).
@@ -360,6 +355,14 @@ static constexpr bool is_magnitude<magnitude<BPs...>> = true;
template<typename T>
concept Magnitude = detail::is_magnitude<T>;
/**
* @brief Free-function access to the value of a Magnitude in a desired type.
*
* Can avoid the need for an unsightly `.template` keyword.
*/
template<typename T>
T get_value(Magnitude auto m) { return m.template value<T>; }
/**
* @brief Convert any positive integer to a Magnitude.
*

36
test/unit_test/runtime/magnitude_test.cpp
View File

@@ -140,25 +140,25 @@ 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.get_value<int>(), 412);
check_same_type_and_value(mag_412.get_value<std::size_t>(), std::size_t{412});
check_same_type_and_value(mag_412.get_value<float>(), 412.0f);
check_same_type_and_value(mag_412.get_value<double>(), 412.0);
check_same_type_and_value(get_value<int>(mag_412), 412);
check_same_type_and_value(get_value<std::size_t>(mag_412), std::size_t{412});
check_same_type_and_value(get_value<float>(mag_412), 412.0f);
check_same_type_and_value(get_value<double>(mag_412), 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.get_value<float>(), 0.125f);
check_same_type_and_value(mag_0p125.get_value<double>(), 0.125);
check_same_type_and_value(get_value<float>(mag_0p125), 0.125f);
check_same_type_and_value(get_value<double>(mag_0p125), 0.125);
}
SECTION("pi to the 1 supplies correct values")
{
constexpr auto pi = pi_to_the<1>();
check_same_type_and_value(pi.get_value<float>(), std::numbers::pi_v<float>);
check_same_type_and_value(pi.get_value<double>(), std::numbers::pi_v<double>);
check_same_type_and_value(pi.get_value<long double>(), std::numbers::pi_v<long double>);
check_same_type_and_value(get_value<float>(pi), std::numbers::pi_v<float>);
check_same_type_and_value(get_value<double>(pi), std::numbers::pi_v<double>);
check_same_type_and_value(get_value<long double>(pi), std::numbers::pi_v<long double>);
}
SECTION("pi to arbitrary power performs computations in most accurate type at compile time")
@@ -170,7 +170,7 @@ TEST_CASE("magnitude converts to numerical value")
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.get_value<float>();
constexpr auto pi_cubed_value = pi_cubed.value<float>;
REQUIRE(pi_cubed_value != via_float);
CHECK(pi_cubed_value == via_long_double);
}
@@ -181,22 +181,22 @@ TEST_CASE("magnitude converts to numerical value")
// 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>().get_value<int8_t>();
// (void)as_magnitude<412>().value<int8_t>;
// Would work for pow<62>:
// (void)pow<63>(as_magnitude<2>()).get_value<int64_t>();
// (void)pow<63>(as_magnitude<2>()).value<int64_t>;
// Would work for pow<63>:
// (void)pow<64>(as_magnitude<2>()).get_value<uint64_t>();
// (void)pow<64>(as_magnitude<2>()).value<uint64_t>;
(void)pow<308>(as_magnitude<10>()).get_value<double>(); // Compiles, correctly.
// (void)pow<309>(as_magnitude<10>()).get_value<double>();
// (void)pow<3099>(as_magnitude<10>()).get_value<double>();
// (void)pow<3099999>(as_magnitude<10>()).get_value<double>();
(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.get_value<int>();
// (void)sqrt_2.value<int>;
}
}