build: CheckCacheVarValues CMake module file added

src/CMakeLists.txt

@@ -27,8 +27,9 @@ set(projectPrefix MP_UNITS_)
 
 list(APPEND CMAKE_MODULE_PATH "${PROJECT_SOURCE_DIR}/cmake")
 
-include(CheckCXXFeatureSupported)
 include(AddMPUnitsModule)
+include(CheckCacheVarValues)
+include(CheckCXXFeatureSupported)
 include(GNUInstallDirs)
 
 # check if libc++ is being used
@@ -77,21 +78,12 @@ option(${projectPrefix}API_NO_CRTP "Enable class definitions without CRTP idiom"
 )
 option(${projectPrefix}API_FREESTANDING "Builds only freestanding part of the library" OFF)
 set(${projectPrefix}API_CONTRACTS GSL-LITE CACHE STRING "Enable contract checking")
+check_cache_var_values(API_CONTRACTS NONE GSL-LITE MS-GSL)
 
 message(STATUS "${projectPrefix}API_STD_FORMAT: ${${projectPrefix}API_STD_FORMAT}")
 message(STATUS "${projectPrefix}API_NO_CRTP: ${${projectPrefix}API_NO_CRTP}")
 message(STATUS "${projectPrefix}API_FREESTANDING: ${${projectPrefix}API_FREESTANDING}")
-
-function(cache_var_values name)
-    set_property(CACHE ${projectPrefix}${name} PROPERTY STRINGS ${ARGN})
-    if(NOT ${projectPrefix}${name} IN_LIST ARGN)
-        message(FATAL_ERROR
-                    "Invalid value '${${projectPrefix}${name}}' provided for a cache variable ${projectPrefix}${name} (${ARGN} allowed)"
-        )
-    endif()
-    message(STATUS "${projectPrefix}${name}: ${${projectPrefix}${name}}")
-endfunction()
-cache_var_values(API_CONTRACTS NONE GSL-LITE MS-GSL)
+message(STATUS "${projectPrefix}API_CONTRACTS: ${${projectPrefix}API_CONTRACTS}")
 
 # validate options
 if(${projectPrefix}API_FREESTANDING AND NOT ${projectPrefix}API_CONTRACTS STREQUAL "NONE")

src/cmake/CheckCacheVarValues.cmake

@@ -0,0 +1,32 @@
+# 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.
+
+cmake_minimum_required(VERSION 3.25)
+
+function(check_cache_var_values name)
+    set_property(CACHE ${projectPrefix}${name} PROPERTY STRINGS ${ARGN})
+    if(NOT ${projectPrefix}${name} IN_LIST ARGN)
+        message(FATAL_ERROR
+                    "Invalid value '${${projectPrefix}${name}}' provided for a cache variable ${projectPrefix}${name} (${ARGN} allowed)"
+        )
+    endif()
+endfunction()