fixed #13821 - use Boost unconditionally if it is available (danmar#7494)

Author: firewave

cmake/findDependencies.cmake

@@ -84,13 +84,16 @@ endif()
 
 find_package(Threads REQUIRED)
 
+if(CMAKE_VERSION VERSION_GREATER_EQUAL "3.30")
+    # avoid legacy warning about Boost lookup in CMake
+    cmake_policy(SET CMP0167 NEW)
+endif()
+
+# we are only using the header-only "container" component so we can unconditionally search for it
 if(USE_BOOST)
-    if(CMAKE_VERSION VERSION_GREATER_EQUAL "3.30")
-        # avoid legacy warning about Boost lookup in CMake
-        cmake_policy(SET CMP0167 NEW)
-    endif()
-    # we are using the header-only "container" component
-    find_package(Boost QUIET)
+    find_package(Boost REQUIRED)
+else()
+    find_package(Boost)
 endif()
 
 find_program(LIBXML2_XMLLINT_EXECUTABLE xmllint)

cmake/options.cmake

@@ -89,7 +89,7 @@ option(DISALLOW_THREAD_EXECUTOR "Disallow usage of ThreadExecutor for -j"
 if(DISALLOW_THREAD_EXECUTOR AND WIN32)
     message(FATAL_ERROR "Cannot disable usage of ThreadExecutor on Windows as no other executor implementation is currently available")
 endif()
-option(USE_BOOST            "Usage of Boost"                                                OFF)
+option(USE_BOOST            "Force usage of Boost"                                                OFF)
 option(USE_BOOST_INT128     "Usage of Boost.Multiprecision 128-bit integer for Mathlib"     OFF)
 if (NOT USE_BOOST AND USE_BOOST_INT128)
     message(FATAL_ERROR "USE_BOOST_INT128 requires USE_BOOST to be enabled")

releasenotes.txt

@@ -22,4 +22,5 @@ Other:
 - added CMake option `ENABLE_CSA_ALPHA` to enable the Clang Static Analyzer alpha checkers
 - Updated TinyXML-2 to v11.0.0
 - The minimum supported Python version has been bumped to 3.7.
+- CMake will now unconditionally use Boost.Containers if available. If CMake option `USE_BOOST` is specified it will now bail out when it is not found.
 -