Gate building Boost.Beast sample on Boost version

Author: wravery

.github/workflows/linux.yml

@@ -41,7 +41,7 @@ jobs:
       run: |
         $cmakeBuildType = '${{ matrix.config }}'
 
-        cmake "-DCMAKE_BUILD_TYPE=$cmakeBuildType" -G Ninja ${{ github.workspace }}
+        cmake "-DCMAKE_BUILD_TYPE=$cmakeBuildType" "-DGRAPHQL_BUILD_HTTP_SAMPLE=OFF" -G Ninja ${{ github.workspace }}
 
     - name: Build
       working-directory: build/

samples/CMakeLists.txt

@@ -9,9 +9,12 @@ add_subdirectory(today)
 add_subdirectory(validation)
 
 if(GRAPHQL_BUILD_HTTP_SAMPLE)
-  if(EXISTS "${Boost_INCLUDE_DIR}/boost/beast.hpp")
-    add_subdirectory(proxy)
-  else()
-    message(WARNING "GRAPHQL_BUILD_HTTP_SAMPLE requires the Boost.Beast header-only library. Not found in ${Boost_INCLUDE_DIR}.")
+  find_package(Boost QUIET)
+  if(Boost_FOUND)
+    if(Boost_VERSIION VERSION_GREATER_EQUAL "1.81.0" AND EXISTS "${Boost_INCLUDE_DIR}/boost/beast.hpp")
+      add_subdirectory(proxy)
+    else()
+      message(WARNING "GRAPHQL_BUILD_HTTP_SAMPLE requires the Boost.Beast header-only library >= 1.81.0, but it was not found in ${Boost_INCLUDE_DIR}.")
+    endif()
   endif()
 endif()