Use target_compile_features to specify C++ standard requirement

CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.1...3.18)
+cmake_minimum_required(VERSION 3.8...3.18)
 
 # Fallback for using newer policies on CMake <3.12.
 if(${CMAKE_VERSION} VERSION_LESS 3.12)
@@ -122,17 +122,9 @@ endif ()
 set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH}
   "${CMAKE_CURRENT_SOURCE_DIR}/support/cmake")
 
-include(cxx14)
+include(CheckCXXCompilerFlag)
 include(JoinPaths)
 
-list(FIND CMAKE_CXX_COMPILE_FEATURES "cxx_variadic_templates" index)
-if (${index} GREATER -1)
-  # Use cxx_variadic_templates instead of more appropriate cxx_std_11 for
-  # compatibility with older CMake versions.
-  set(FMT_REQUIRED_FEATURES cxx_variadic_templates)
-endif ()
-message(STATUS "Required features: ${FMT_REQUIRED_FEATURES}")
-
 if (FMT_MASTER_PROJECT AND NOT DEFINED CMAKE_CXX_VISIBILITY_PRESET)
   set_verbose(CMAKE_CXX_VISIBILITY_PRESET hidden CACHE STRING
               "Preset for the export of private symbols")
@@ -239,7 +231,7 @@ if (FMT_MODULE)
   enable_module(fmt)
 endif ()
 
-target_compile_features(fmt INTERFACE ${FMT_REQUIRED_FEATURES})
+target_compile_features(fmt PUBLIC cxx_std_11)
 
 target_include_directories(fmt ${FMT_SYSTEM_HEADERS_ATTRIBUTE} PUBLIC
   $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/include>
@@ -270,7 +262,7 @@ add_library(fmt-header-only INTERFACE)
 add_library(fmt::fmt-header-only ALIAS fmt-header-only)
 
 target_compile_definitions(fmt-header-only INTERFACE FMT_HEADER_ONLY=1)
-target_compile_features(fmt-header-only INTERFACE ${FMT_REQUIRED_FEATURES})
+target_compile_features(fmt-header-only INTERFACE cxx_std_11)
 
 target_include_directories(fmt-header-only ${FMT_SYSTEM_HEADERS_ATTRIBUTE} INTERFACE
   $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/include>

test/CMakeLists.txt

@@ -109,7 +109,7 @@ if (FMT_MODULE)
   # If module support is present the module tests require a
   # test-only module to be built from {fmt}
   add_library(test-module OBJECT ${CMAKE_SOURCE_DIR}/src/fmt.cc)
-  target_compile_features(test-module PUBLIC ${FMT_REQUIRED_FEATURES})
+  target_compile_features(test-module PUBLIC cxx_std_11)
   target_include_directories(test-module PUBLIC
     $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/include>)
   enable_module(test-module)

test/add-subdirectory-test/CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.1...3.18)
+cmake_minimum_required(VERSION 3.8...3.18)
 
 project(fmt-test CXX)
 

test/compile-error-test/CMakeLists.txt

@@ -1,6 +1,6 @@
 # Test if compile errors are produced where necessary.
 
-cmake_minimum_required(VERSION 3.1...3.18)
+cmake_minimum_required(VERSION 3.8...3.18)
 project(compile-error-test CXX)
 
 set(fmt_headers "
@@ -64,7 +64,7 @@ function (run_tests)
   ")
 
   file(WRITE "${CMAKE_CURRENT_BINARY_DIR}/test/CMakeLists.txt" "
-    cmake_minimum_required(VERSION 3.1...3.18)
+    cmake_minimum_required(VERSION 3.8...3.18)
     project(tests CXX)
     add_subdirectory(${FMT_DIR} fmt)
     ${cmake_targets}

test/find-package-test/CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.1...3.18)
+cmake_minimum_required(VERSION 3.8...3.18)
 
 project(fmt-test)
 

test/fuzzing/CMakeLists.txt

@@ -22,7 +22,7 @@ function(add_fuzzer source)
   if (FMT_FUZZ_LDFLAGS)
     target_link_libraries(${name} PRIVATE ${FMT_FUZZ_LDFLAGS})
   endif ()
-  target_compile_features(${name} PRIVATE cxx_generic_lambdas)
+  target_compile_features(${name} PRIVATE cxx_std_14)
 endfunction()
 
 foreach (source chrono-duration.cc chrono-timepoint.cc float.cc named-arg.cc one-arg.cc two-args.cc)

test/gtest/CMakeLists.txt

@@ -9,6 +9,7 @@ add_library(gtest STATIC
   gmock-gtest-all.cc gmock/gmock.h gtest/gtest.h gtest/gtest-spi.h)
 target_compile_definitions(gtest PUBLIC GTEST_HAS_STD_WSTRING=1)
 target_include_directories(gtest SYSTEM PUBLIC .)
+target_compile_features(gtest PUBLIC cxx_std_11)
 
 find_package(Threads)
 if (Threads_FOUND)
@@ -17,9 +18,10 @@ else ()
   target_compile_definitions(gtest PUBLIC GTEST_HAS_PTHREAD=0)
 endif ()
 
-# Workaround GTest bug https://github.com/google/googletest/issues/705.
-fmt_check_cxx_compiler_flag(
-  -fno-delete-null-pointer-checks HAVE_FNO_DELETE_NULL_POINTER_CHECKS)
+# Workaround GTest bug https://github.com/google/googletest/issues/705
+if (NOT MSVC)
+  check_cxx_compiler_flag(-fno-delete-null-pointer-checks HAVE_FNO_DELETE_NULL_POINTER_CHECKS)
+endif ()
 if (HAVE_FNO_DELETE_NULL_POINTER_CHECKS)
   target_compile_options(gtest PUBLIC -fno-delete-null-pointer-checks)
 endif ()

test/static-export-test/CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.1...3.18)
+cmake_minimum_required(VERSION 3.8...3.18)
 
 project(fmt-link CXX)