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rolandreichweinbmwrolandreichweinbmw
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Added missing rational arithmetic functions from <ratio> (#1014)
* Added ratio traits * Fix unused test suite in < C++14 case * Port to C++11 * Fix header includes
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‎include/etl/ratio.h‎

Lines changed: 152 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -33,6 +33,8 @@ SOFTWARE.
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#include "platform.h"
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#include "type_traits.h"
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#include <stddef.h>
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#include <stdint.h>
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@@ -41,17 +43,17 @@ SOFTWARE.
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namespace etl
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{
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template <size_t NUM, size_t DEN = 1UL>
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template <intmax_t NUM, intmax_t DEN = 1UL>
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struct ratio
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{
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static ETL_CONSTANT intmax_t num = NUM;
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static ETL_CONSTANT intmax_t den = DEN;
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};
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template <size_t NUM, size_t DEN>
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template <intmax_t NUM, intmax_t DEN>
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ETL_CONSTANT intmax_t ratio<NUM, DEN>::num;
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template <size_t NUM, size_t DEN>
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template <intmax_t NUM, intmax_t DEN>
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ETL_CONSTANT intmax_t ratio<NUM, DEN>::den;
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#if INT_MAX > INT32_MAX
@@ -97,6 +99,153 @@ namespace etl
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/// An approximation of e.
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typedef ratio<326, 120> ratio_e;
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#if ETL_USING_CPP11
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namespace private_ratio
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{
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// Primary template for GCD calculation
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template <typename T, T A, T B, bool = (B == 0)>
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struct ratio_gcd;
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// Specialisation for the case when B is not zero
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template <typename T, T A, T B>
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struct ratio_gcd<T, A, B, false>
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{
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static constexpr T value = ratio_gcd<T, B, A % B>::value;
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};
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// Specialisation for the case when B is zero
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template <typename T, T A, T B>
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struct ratio_gcd<T, A, B, true>
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{
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static constexpr T value = (A < 0) ? -A : A;
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};
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// Primary template for LCM calculation
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template <typename T, T A, T B>
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struct ratio_lcm
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{
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private:
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static constexpr T product = ((A * B) < 0) ? -(A * B) : A * B;
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public:
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static constexpr T value = product / ratio_gcd<T, A, B>::value;
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};
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template<typename R1>
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struct ratio_reduce
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{
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private:
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static ETL_CONSTEXPR11 intmax_t gcd = etl::private_ratio::ratio_gcd<intmax_t, R1::num, R1::den>::value;
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public:
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using value = ratio<R1::num / gcd, R1::den / gcd>;
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};
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template<typename R1, typename R2>
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struct ratio_add
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{
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private:
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static ETL_CONSTEXPR11 intmax_t lcm = etl::private_ratio::ratio_lcm<intmax_t, R1::den, R2::den>::value;
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public:
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using value = typename ratio_reduce<ratio<R1::num * lcm / R1::den + R2::num * lcm / R2::den, lcm>>::value;
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};
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template<typename R1, typename R2>
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struct ratio_subtract
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{
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public:
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using value = typename ratio_add<R1, ratio<-R2::num, R2::den>>::value;
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};
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template<typename R1, typename R2>
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struct ratio_multiply
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{
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private:
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static ETL_CONSTEXPR11 intmax_t gcd1 = etl::private_ratio::ratio_gcd<intmax_t, R1::num, R2::den>::value;
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static ETL_CONSTEXPR11 intmax_t gcd2 = etl::private_ratio::ratio_gcd<intmax_t, R2::num, R1::den>::value;
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public:
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using value = ratio<(R1::num / gcd1) * (R2::num / gcd2), (R1::den / gcd2) * (R2::den / gcd1)>;
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};
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template<typename R1, typename R2>
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struct ratio_divide
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{
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public:
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using value = typename ratio_multiply<R1, ratio<R2::den, R2::num>>::value;
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};
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}
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template<typename R1, typename R2>
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using ratio_add = typename private_ratio::ratio_add<R1, R2>::value;
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template<typename R1, typename R2>
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using ratio_subtract = typename private_ratio::ratio_subtract<R1, R2>::value;
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template<typename R1, typename R2>
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using ratio_multiply = typename private_ratio::ratio_multiply<R1, R2>::value;
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template<typename R1, typename R2>
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using ratio_divide = typename private_ratio::ratio_divide<R1, R2>::value;
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template<typename R1, typename R2>
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struct ratio_equal: etl::integral_constant<bool, (R1::num == R2::num && R1::den == R2::den)>
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{
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};
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template<typename R1, typename R2>
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struct ratio_not_equal: etl::integral_constant<bool, (R1::num != R2::num || R1::den != R2::den)>
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{
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};
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template<typename R1, typename R2>
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struct ratio_less: etl::integral_constant<bool, (R1::num * R2::den < R2::num * R1::den)>
211+
{
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};
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template<typename R1, typename R2>
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struct ratio_less_equal: etl::integral_constant<bool, (R1::num * R2::den <= R2::num * R1::den)>
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{
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};
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template<typename R1, typename R2>
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struct ratio_greater: etl::integral_constant<bool, (R1::num * R2::den > R2::num * R1::den)>
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{
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};
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template<typename R1, typename R2>
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struct ratio_greater_equal: etl::integral_constant<bool, (R1::num * R2::den >= R2::num * R1::den)>
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{
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};
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#if ETL_USING_CPP14
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template<typename R1, typename R2>
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ETL_CONSTEXPR14 bool ratio_equal_v = ratio_equal<R1, R2>::value;
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template<typename R1, typename R2>
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ETL_CONSTEXPR14 bool ratio_not_equal_v = ratio_not_equal<R1, R2>::value;
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template<typename R1, typename R2>
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ETL_CONSTEXPR14 bool ratio_less_v = ratio_less<R1, R2>::value;
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template<typename R1, typename R2>
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ETL_CONSTEXPR14 bool ratio_less_equal_v = ratio_less_equal<R1, R2>::value;
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template<typename R1, typename R2>
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ETL_CONSTEXPR14 bool ratio_greater_v = ratio_greater<R1, R2>::value;
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template<typename R1, typename R2>
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ETL_CONSTEXPR14 bool ratio_greater_equal_v = ratio_greater_equal<R1, R2>::value;
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#endif
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#endif
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}
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#endif

‎test/CMakeLists.txt‎

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@@ -222,6 +222,7 @@ add_executable(etl_tests
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test_queue_spsc_locked.cpp
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test_queue_spsc_locked_small.cpp
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test_random.cpp
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test_ratio.cpp
225226
test_reference_flat_map.cpp
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test_reference_flat_multimap.cpp
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test_reference_flat_multiset.cpp

‎test/test_ratio.cpp‎

Lines changed: 144 additions & 0 deletions
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@@ -0,0 +1,144 @@
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/******************************************************************************
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The MIT License(MIT)
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Embedded Template Library.
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https://github.com/ETLCPP/etl
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https://www.etlcpp.com
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Copyright(c) 2025 BMW AG
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Permission is hereby granted, free of charge, to any person obtaining a copy
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of this software and associated documentation files(the "Software"), to deal
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in the Software without restriction, including without limitation the rights
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to use, copy, modify, merge, publish, distribute, sublicense, and / or sell
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copies of the Software, and to permit persons to whom the Software is
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furnished to do so, subject to the following conditions :
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The above copyright notice and this permission notice shall be included in all
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copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.IN NO EVENT SHALL THE
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AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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SOFTWARE.
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******************************************************************************/
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#include "unit_test_framework.h"
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31+
#include "etl/ratio.h"
32+
33+
#if ETL_USING_CPP11
34+
namespace
35+
{
36+
SUITE(test_ratio)
37+
{
38+
//*************************************************************************
39+
TEST(test_ratio_add)
40+
{
41+
using r1 = etl::ratio<1, 2>;
42+
using r2 = etl::ratio<2, 3>;
43+
using r3 = etl::ratio_add<r1, r2>;
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45+
CHECK((etl::ratio_equal<r3, etl::ratio<7, 6>>::value));
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CHECK((!etl::ratio_equal<r3, etl::ratio<1, 6>>::value));
47+
}
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49+
//*************************************************************************
50+
TEST(test_ratio_subtract)
51+
{
52+
using r1 = etl::ratio<1, 2>;
53+
using r2 = etl::ratio<2, 3>;
54+
using r3 = etl::ratio_subtract<r1, r2>;
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56+
CHECK((etl::ratio_equal<r3, etl::ratio<-1, 6>>::value));
57+
CHECK((!etl::ratio_equal<r3, etl::ratio<-2, 6>>::value));
58+
}
59+
60+
//*************************************************************************
61+
TEST(test_ratio_multiply)
62+
{
63+
using r1 = etl::ratio<1, 2>;
64+
using r2 = etl::ratio<2, 3>;
65+
using r3 = etl::ratio_multiply<r1, r2>;
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CHECK((etl::ratio_equal<r3, etl::ratio<1, 3>>::value));
68+
CHECK((!etl::ratio_equal<r3, etl::ratio<1, 4>>::value));
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}
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71+
//*************************************************************************
72+
TEST(test_ratio_divide)
73+
{
74+
using r1 = etl::ratio<1, 2>;
75+
using r2 = etl::ratio<2, 3>;
76+
using r3 = etl::ratio_divide<r1, r2>;
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CHECK((!etl::ratio_not_equal<r3, etl::ratio<3, 4>>::value));
79+
CHECK((etl::ratio_not_equal<r3, etl::ratio<4, 3>>::value));
80+
}
81+
82+
//*************************************************************************
83+
TEST(test_ratio_equal)
84+
{
85+
using r1 = etl::ratio<1, 2>;
86+
using r2 = etl::ratio<2, 3>;
87+
88+
CHECK((etl::ratio_equal<r1, r1>::value));
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CHECK((!etl::ratio_equal<r1, r2>::value));
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}
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//*************************************************************************
93+
TEST(test_ratio_not_equal)
94+
{
95+
using r1 = etl::ratio<1, 2>;
96+
using r2 = etl::ratio<2, 3>;
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98+
CHECK((!etl::ratio_not_equal<r1, r1>::value));
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CHECK((etl::ratio_not_equal<r1, r2>::value));
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}
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//*************************************************************************
103+
TEST(test_ratio_less)
104+
{
105+
using r1 = etl::ratio<1, 2>;
106+
using r2 = etl::ratio<2, 3>;
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CHECK((etl::ratio_less<r1, r2>::value));
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CHECK((!etl::ratio_less<r2, r1>::value));
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}
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//*************************************************************************
113+
TEST(test_ratio_less_equal)
114+
{
115+
using r1 = etl::ratio<1, 2>;
116+
using r2 = etl::ratio<2, 3>;
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118+
CHECK((etl::ratio_less_equal<r1, r1>::value));
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CHECK((etl::ratio_less_equal<r1, r2>::value));
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}
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//*************************************************************************
123+
TEST(test_ratio_greater)
124+
{
125+
using r1 = etl::ratio<4, 3>;
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using r2 = etl::ratio<2, 3>;
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CHECK((etl::ratio_greater<r1, r2>::value));
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CHECK((!etl::ratio_greater<r2, r1>::value));
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}
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//*************************************************************************
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TEST(test_ratio_greater_equal)
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{
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using r1 = etl::ratio<4, 3>;
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using r2 = etl::ratio<2, 3>;
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CHECK((etl::ratio_greater_equal<r1, r1>::value));
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CHECK((etl::ratio_greater_equal<r1, r2>::value));
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}
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};
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}
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#endif

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