Modifications to build C++ with Visual Studio 2026 and the v145 toolset. (#9359)

* Modifications to build C++ with Visual Studio 2026 and the v145 toolset.

* Fixes linker settings for rocksdb for Debug and Release builds

* module is a C++ 20 keyword. Explicitly stating namespace allows cpp20 projects to build against the library

* Fixes crash when initializing an object with the initialize function when some of the attributes are empty, {}, or omitted, std::nullopt

* cleanup for vs2026 v145 toolset per @aothms review

* Fixes bug, IfcCurveSegment.setStartLength was setSegmentLength in alignment_helper.cpp

* Bumps boost to 1.92

cmake/CMakeLists.txt

@@ -178,26 +178,31 @@ if((BUILD_CONVERT OR BUILD_GEOMSERVER OR BUILD_IFCPYTHON) AND(NOT BUILD_IFCGEOM)
     set(BUILD_IFCGEOM ON)
 endif()
 
-find_program(CCACHE_FOUND ccache)
-if(CCACHE_FOUND)
-    message(STATUS "`ccache` is found, using it as a compiler launcher.")
-    set_property(GLOBAL PROPERTY RULE_LAUNCH_COMPILE "${CCACHE_FOUND}")
-    if(MSVC)
-        # By default Visual Studio generators will use /Zi which is not compatible
-        # with ccache, so tell Visual Studio to use /Z7 instead.
-        set(CMAKE_MSVC_DEBUG_INFORMATION_FORMAT "$<$<CONFIG:Debug,RelWithDebInfo>:Embedded>")
-        # Not needed for Ninja.
-        if(CMAKE_GENERATOR MATCHES "Visual Studio")
-            file(COPY_FILE
-                ${CCACHE_FOUND} ${CMAKE_BINARY_DIR}/cl.exe
-                ONLY_IF_DIFFERENT)
-            set(CMAKE_VS_GLOBALS
-                "CLToolExe=cl.exe"
-                "CLToolPath=${CMAKE_BINARY_DIR}"
-                "UseMultiToolTask=true"
-            )
+option(USE_CCACHE "Use ccache as a compiler launcher if it is found" OFF)
+if(USE_CCACHE)
+    find_program(CCACHE_FOUND ccache)
+    if(CCACHE_FOUND)
+        message(STATUS "`ccache` is found, using it as a compiler launcher.")
+        set_property(GLOBAL PROPERTY RULE_LAUNCH_COMPILE "${CCACHE_FOUND}")
+        if(MSVC)
+            # By default Visual Studio generators will use /Zi which is not compatible
+            # with ccache, so tell Visual Studio to use /Z7 instead.
+            set(CMAKE_MSVC_DEBUG_INFORMATION_FORMAT "$<$<CONFIG:Debug,RelWithDebInfo>:Embedded>")
+            # Not needed for Ninja.
+            if(CMAKE_GENERATOR MATCHES "Visual Studio")
+                file(COPY_FILE
+                    ${CCACHE_FOUND} ${CMAKE_BINARY_DIR}/cl.exe
+                    ONLY_IF_DIFFERENT)
+                set(CMAKE_VS_GLOBALS
+                    "CLToolExe=cl.exe"
+                    "CLToolPath=${CMAKE_BINARY_DIR}"
+                    "UseMultiToolTask=true"
+                )
+            endif()
         endif()
     endif()
+else()
+    message(STATUS "ccache usage disabled via USE_CCACHE=OFF")
 endif()
 
 if(MSVC AND MSVC_PARALLEL_BUILD)
@@ -311,12 +316,25 @@ if (WITH_ROCKSDB)
     set(SWIG_DEFINES ${SWIG_DEFINES} -DIFOPSH_WITH_ROCKSDB)
     # See https://github.com/facebook/rocksdb/issues/981.
     if(TARGET RocksDB::rocksdb)
-        target_link_libraries(IFCOPENSHELL_RocksDB INTERFACE RocksDB::rocksdb)
+        set(IFCOPENSHELL_ROCKSDB_IMPORTED_TARGET RocksDB::rocksdb)
     elseif(TARGET RocksDB::rocksdb-shared)
-        target_link_libraries(IFCOPENSHELL_RocksDB INTERFACE RocksDB::rocksdb-shared)
+        set(IFCOPENSHELL_ROCKSDB_IMPORTED_TARGET RocksDB::rocksdb-shared)
     else()
         message(FATAL_ERROR "RocksDB found but neither RocksDB::rocksdb nor RocksDB::rocksdb-shared target exists")
     endif()
+    # Our win/build-deps.cmd builds RocksDB separately per Debug/Release config into the
+    # same install prefix, so the imported target only ever has DEBUG and RELEASE listed in
+    # IMPORTED_CONFIGURATIONS. On a multi-config generator (Visual Studio), CMake maps any
+    # unmatched build config to the *first* entry of that list, which happens to be DEBUG
+    # (RocksDBTargets-debug.cmake sorts before RocksDBTargets-release.cmake). Without an
+    # explicit mapping, RelWithDebInfo and MinSizeRel builds would end up linking the
+    # /MDd-flavored rocksdb_d.lib into an /MD (NDEBUG) binary, causing a CRT/runtime-library
+    # mismatch that depends on nothing but that alphabetical ordering.
+    set_target_properties(${IFCOPENSHELL_ROCKSDB_IMPORTED_TARGET} PROPERTIES
+        MAP_IMPORTED_CONFIG_RELWITHDEBINFO RELEASE
+        MAP_IMPORTED_CONFIG_MINSIZEREL RELEASE
+    )
+    target_link_libraries(IFCOPENSHELL_RocksDB INTERFACE ${IFCOPENSHELL_ROCKSDB_IMPORTED_TARGET})
 
     if (WITH_ZSTD)
         # @todo do we actually need the zstd include dir or rather just pass