From 36b4d51bafc13dcdfbeeb23be7e12bb03a9e98d0 Mon Sep 17 00:00:00 2001 From: John Wellbelove Date: Sun, 16 Mar 2025 19:06:34 +0000 Subject: [PATCH] Added etl::index_of_type as a complement to etl::nth_type --- include/etl/index_of_type.h | 80 +++++++++++++++++++++++++++++++++++++ test/test_index_of_type.cpp | 58 +++++++++++++++++++++++++++ 2 files changed, 138 insertions(+) create mode 100644 include/etl/index_of_type.h create mode 100644 test/test_index_of_type.cpp diff --git a/include/etl/index_of_type.h b/include/etl/index_of_type.h new file mode 100644 index 00000000..5546ad53 --- /dev/null +++ b/include/etl/index_of_type.h @@ -0,0 +1,80 @@ +/****************************************************************************** +The MIT License(MIT) + +Embedded Template Library. +https://github.com/ETLCPP/etl +https://www.etlcpp.com + +Copyright(c) 2025 John Wellbelove + +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. +******************************************************************************/ + +#ifndef ETL_INDEX_OF_TYPE_INCLUDED +#define ETL_INDEX_OF_TYPE_INCLUDED + +#include "platform.h" +#include "static_assert.h" +#include "integral_limits.h" + +namespace etl +{ +#if ETL_USING_CPP11 + + //*************************************************************************** + /// Defines a no-position constant. + //*************************************************************************** + static ETL_CONSTANT size_t index_of_type_npos = etl::integral_limits::max; + + //*************************************************************************** + /// Finds the index of a type in a variadic type parameter. + //*************************************************************************** + template + struct index_of_type; + + //*************************************************************************** + /// Finds the index of a type in a variadic type parameter. + //*************************************************************************** + template + struct index_of_type : public etl::integral_constant::value ? 0 : + (etl::index_of_type::value == etl::index_of_type_npos ? etl::index_of_type_npos : + etl::index_of_type::value + 1)> + { + }; + + //*************************************************************************** + /// Finds the index of a type in a variadic type parameter. + /// No types left. + //*************************************************************************** + template + struct index_of_type : public etl::integral_constant + { + }; + +#if ETL_USING_CPP17 + //*************************************************************************** + /// Finds the index of a type in a variadic type parameter. + //*************************************************************************** + template + inline constexpr size_t index_of_type_v = etl::index_of_type::value; +#endif +#endif +} + +#endif diff --git a/test/test_index_of_type.cpp b/test/test_index_of_type.cpp new file mode 100644 index 00000000..60d211e8 --- /dev/null +++ b/test/test_index_of_type.cpp @@ -0,0 +1,58 @@ +/****************************************************************************** +The MIT License(MIT) + +Embedded Template Library. +https://github.com/ETLCPP/etl +https://www.etlcpp.com + +Copyright(c) 2025 John Wellbelove + +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 "unit_test_framework.h" + +#include "etl/index_of_type.h" +#include + +namespace +{ + SUITE(test_index_of_type) + { + //************************************************************************* + TEST(test_index_of_type) + { + CHECK_EQUAL(0, (etl::index_of_type::value)); + CHECK_EQUAL(1, (etl::index_of_type::value)); + CHECK_EQUAL(2, (etl::index_of_type::value)); + CHECK_EQUAL(etl::index_of_type_npos, (etl::index_of_type::value)); + } + + //************************************************************************* +#if ETL_USING_CPP17 + TEST(test_index_of_type_v) + { + CHECK_EQUAL(0, (etl::index_of_type_v)); + CHECK_EQUAL(1, (etl::index_of_type_v)); + CHECK_EQUAL(2, (etl::index_of_type_v)); + CHECK_EQUAL(etl::index_of_type_npos, (etl::index_of_type_v)); + } +#endif + } +}