updated build system

cmake/flags.cmake

@@ -60,7 +60,7 @@ list(APPEND PROJECT_CFLAGS_LIST
 list(APPEND PROJECT_CXXFLAGS_LIST
   ${PROJECT_COMMON_FLAG_LIST}
   -fext-numeric-literals
-  -std=c++${CMAKE_CXX_STANDARD}
+  -std=gnu++${CMAKE_CXX_STANDARD}
 )
 
 if(PROJECT_STATIC_LINK)

cmake/libraries/boost.cmake

@@ -69,12 +69,14 @@ if(PROJECT_ENABLE_BOOST)
       --prefix=${PROJECT_EXTERNAL_BUILD_ROOT}
       address-model=64
       architecture=${BOOST_ARCH}
-      cxxflags=-std=c++${CMAKE_CXX_STANDARD}
+      cxxstd=20
+      cxxstd-dialect=gnu
+      cxxflags=-std=gnu++${CMAKE_CXX_STANDARD}
       cxxstd=${CMAKE_CXX_STANDARD}
       define=BOOST_ASIO_HAS_STD_STRING_VIEW
       define=BOOST_SYSTEM_NO_DEPRECATED
       link=${BOOST_LINK}
-      linkflags=-std=c++${CMAKE_CXX_STANDARD}
+      linkflags=-std=gnu++${CMAKE_CXX_STANDARD}
       threading=multi
       variant=${BOOST_BUILD_TYPE_LOWER}
     )

cmake/versions.cmake

@@ -15,7 +15,7 @@ set(FLAC_VERSION 1.4.3)
 set(FMT_VERSION 10.2.1)
 set(FONTCONFIG_VERSION 2.15.0)
 set(FREETYPE2_VERSION 2.13.2)
-set(GCC_VERSION 13.2.0)
+set(GCC_VERSION 14.2.0)
 set(GTEST_VERSION 1.15.0)
 set(GTKMM_VERSION 3.0)
 set(ICU_VERSION 75-1)