Compiler version specific configuration support added

CMakeLists.txt

@@ -25,16 +25,15 @@ project(units)
 
 # set path to custom cmake modules
 list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake")
-list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake/common/cmake")
 
 # include common tools and workarounds
-include(tools)
+include(common/cmake/tools)
 
 # use Conan configuration if available
 conan_init(cmake)
 
 # compilation options and flags used in a project development process
-include(compile_flags)
+include(common/cmake/compile_flags)
 
 # add project code
 add_subdirectory(src)

cmake/check_features.cmake

@@ -0,0 +1,30 @@
+# 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.
+
+set(CMAKE_REQUIRED_FLAGS -std=c++2a)
+
+include(CheckTypeSize)
+
+set(CMAKE_EXTRA_INCLUDE_FILES type_traits)
+check_type_size("std::type_identity<int>" UNITS_HAS_STD_TYPE_IDENTITY LANGUAGE CXX)
+
+configure_file(../cmake/config.h.in include/units/bits/config.h)

cmake/config.h.in

@@ -0,0 +1,25 @@
+// 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.
+
+#pragma once
+
+#cmakedefine UNITS_HAS_STD_TYPE_IDENTITY

conanfile.py

@@ -85,4 +85,6 @@ class UnitsConan(ConanFile):
         self.cpp_info.includedirs = ['include']
 
     def package_id(self):
-        self.info.header_only()
+        self.info.settings.clear()
+        self.info.settings.compiler = self.settings.compiler
+        self.info.settings.compiler.version = self.settings.compiler.version

src/CMakeLists.txt

@@ -29,10 +29,13 @@ project(units
 )
 
 # set path to custom cmake modules
-list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/../cmake/common/cmake")
+list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/../cmake")
 
 # include common tools and workarounds
-include(tools)
+include(common/cmake/tools)
+
+# check availability of C++20 features
+include(check_features)
 
 # library definition
 add_library(units INTERFACE)
@@ -59,7 +62,7 @@ target_link_libraries(units
 target_include_directories(units
     INTERFACE
         $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
-        $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}>
+        $<BUILD_INTERFACE:${CMAKE_CURRENT_BINARY_DIR}/include>
         $<INSTALL_INTERFACE:include>
 )
 add_library(mp::units ALIAS units)
@@ -75,6 +78,10 @@ install(DIRECTORY include/units
     DESTINATION include
     COMPONENT Devel
 )
+install(DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/include/units
+    DESTINATION include
+    COMPONENT Devel
+)
 
 # generate configuration files and install the package
 configure_and_install(../cmake/common/cmake/simple_package-config.cmake.in mp SameMajorVersion)

src/include/units/bits/hacks.h

@@ -22,10 +22,13 @@
 
 #pragma once
 
+#include <units/bits/config.h>
 #include <experimental/ranges/concepts>
 
 namespace std {
 
+#ifndef UNITS_HAS_STD_TYPE_IDENTITY
+
   // type_identity
   template<typename T>
   struct type_identity { using type = T; };
@@ -33,6 +36,8 @@ namespace std {
   template<typename T>
   using type_identity_t = typename type_identity<T>::type;
 
+#endif // UNITS_HAS_STD_TYPE_IDENTITY
+
   // concepts
   using experimental::ranges::Same;
   using experimental::ranges::Integral;