boostorg · fdr400 · Mar 3, 2026 · Mar 4, 2026 · Mar 5, 2026 · Mar 5, 2026
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
@@ -94,10 +94,28 @@ jobs:
           make -j"$(nproc)"
           make install
 
+      - name: Run modules tests
+        if: ${{matrix.toolset == 'clang-19'}}
+        run: |
+          cd ../boost-root/libs/$LIBRARY
+          cmake -S test/cmake_subdir_test \
+                -B build_module \
+                -GNinja \
+                -DBOOST_USE_MODULES=1 \
+                -DBUILD_TESTING=1 \
+                -DCMAKE_CXX_STANDARD=23 \
+                -DCMAKE_CXX_COMPILER=${{matrix.compiler}} \
+                -DCMAKE_CXX_FLAGS="-stdlib=libc++ -I$HOME/.local/include" \
+                -DCMAKE_EXE_LINKER_FLAGS="-L$HOME/.local" \
+                -DCMAKE_CXX_MODULE_STD=ON \
+                -DCMAKE_EXPERIMENTAL_CXX_IMPORT_STD=0e5b6991-d74f-4b3d-a41c-cf096e0b2508
+          cmake --build build_module
+          ctest --test-dir build_module -VV
+          rm -rf build_module
+
       - name: Run modules tests without 'import std;'
         if: ${{matrix.toolset == 'clang-19'}}
         run: |
-          pwd
           cd ../boost-root/libs/$LIBRARY
           cmake -S test/cmake_subdir_test \
                 -B build_module \

diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -7,18 +7,24 @@ cmake_minimum_required(VERSION 3.8...4.20)
 
 project(boost_stacktrace VERSION "${BOOST_SUPERPROJECT_VERSION}" LANGUAGES CXX)
 
-function(stacktrace_add_module name)
+function(stacktrace_add_module name import_std)
   target_sources(${name}
     PUBLIC
       FILE_SET CXX_MODULES
       BASE_DIRS "${CMAKE_CURRENT_LIST_DIR}/modules"
       FILES "${CMAKE_CURRENT_LIST_DIR}/modules/${name}.cppm"
   )
-  target_compile_features(${name} PUBLIC cxx_std_20)
   target_compile_definitions(${name} PUBLIC BOOST_USE_MODULES)
+
+  if(${import_std})
+    target_compile_features(${name} PUBLIC cxx_std_23)
+    target_compile_definitions(${name} PRIVATE BOOST_STACKTRACE_USE_STD_MODULE)
+  else()
+    target_compile_features(${name} PUBLIC cxx_std_20)
+  endif()
 endfunction()
 
-function(stacktrace_add_library suffix opt public_libs libs defs add_module)
+function(stacktrace_add_library suffix opt public_libs libs defs add_module import_std)
 
   if(NOT opt)
     return()
@@ -50,7 +56,7 @@ function(stacktrace_add_library suffix opt public_libs libs defs add_module)
   )
 
   if (add_module)
-    stacktrace_add_module(boost_stacktrace_${suffix})
+    stacktrace_add_module(boost_stacktrace_${suffix} ${import_std})
   else()
     target_sources(boost_stacktrace_${suffix}
       PRIVATE
@@ -129,23 +135,36 @@ else()
   set(_enable_non_noop_backend FALSE)
 endif()
 
-if(NOT BOOST_USE_MODULES)
+if(BOOST_USE_MODULES)
+  if(NOT CMAKE_CXX_STANDARD)
+    set(CMAKE_CXX_STANDARD 20)
+  endif()
+  if ((CMAKE_CXX_STANDARD IN_LIST CMAKE_CXX_COMPILER_IMPORT_STD) AND CMAKE_CXX_MODULE_STD)
+    message(STATUS "Using `import std;`")
+    set(__import_std ON)
+  else()
+    message(STATUS "`import std;` is not available")
+    set(__import_std OFF)
+  endif()
+  unset(__standard)
+else()
   set(BOOST_USE_MODULES OFF)
+  set(__import_std OFF)
 endif()
 
-stacktrace_add_library(dump ${_enable_non_noop_backend} "" "" "" ${BOOST_USE_MODULES})
-stacktrace_add_library(noop ${BOOST_STACKTRACE_ENABLE_NOOP} "" "" "" ${BOOST_USE_MODULES})
-stacktrace_add_library(backtrace ${BOOST_STACKTRACE_ENABLE_BACKTRACE} Boost::stacktrace_dump "backtrace;${CMAKE_DL_LIBS}" "" ${BOOST_USE_MODULES})
-stacktrace_add_library(addr2line ${BOOST_STACKTRACE_ENABLE_ADDR2LINE} Boost::stacktrace_dump "${CMAKE_DL_LIBS}" "" ${BOOST_USE_MODULES})
-stacktrace_add_library(basic ${BOOST_STACKTRACE_ENABLE_BASIC} Boost::stacktrace_dump "${CMAKE_DL_LIBS}" "" ${BOOST_USE_MODULES})
-stacktrace_add_library(windbg ${BOOST_STACKTRACE_ENABLE_WINDBG} Boost::stacktrace_dump "dbgeng;ole32" "_GNU_SOURCE=1" ${BOOST_USE_MODULES})
-stacktrace_add_library(windbg_cached ${BOOST_STACKTRACE_ENABLE_WINDBG_CACHED} Boost::stacktrace_dump "dbgeng;ole32" "_GNU_SOURCE=1" ${BOOST_USE_MODULES})
+stacktrace_add_library(dump ${_enable_non_noop_backend} "" "" "" ${BOOST_USE_MODULES} ${__import_std})
+stacktrace_add_library(noop ${BOOST_STACKTRACE_ENABLE_NOOP} "" "" "" ${BOOST_USE_MODULES} ${__import_std})
+stacktrace_add_library(backtrace ${BOOST_STACKTRACE_ENABLE_BACKTRACE} Boost::stacktrace_dump "backtrace;${CMAKE_DL_LIBS}" "" ${BOOST_USE_MODULES} ${__import_std})
+stacktrace_add_library(addr2line ${BOOST_STACKTRACE_ENABLE_ADDR2LINE} Boost::stacktrace_dump "${CMAKE_DL_LIBS}" "" ${BOOST_USE_MODULES} ${__import_std})
+stacktrace_add_library(basic ${BOOST_STACKTRACE_ENABLE_BASIC} Boost::stacktrace_dump "${CMAKE_DL_LIBS}" "" ${BOOST_USE_MODULES} ${__import_std})
+stacktrace_add_library(windbg ${BOOST_STACKTRACE_ENABLE_WINDBG} Boost::stacktrace_dump "dbgeng;ole32" "_GNU_SOURCE=1" ${BOOST_USE_MODULES} ${__import_std})
+stacktrace_add_library(windbg_cached ${BOOST_STACKTRACE_ENABLE_WINDBG_CACHED} Boost::stacktrace_dump "dbgeng;ole32" "_GNU_SOURCE=1" ${BOOST_USE_MODULES} ${__import_std})
 
 # boost_stacktrace, default library
 
 if(BOOST_USE_MODULES)
   add_library(boost_stacktrace)
-  stacktrace_add_module(boost_stacktrace boost_stacktrace)
+  stacktrace_add_module(boost_stacktrace ${__import_std})
   set(__scope PUBLIC)
 
   foreach(backend noop backtrace addr2line basic windbg windbg_cached)
@@ -157,6 +176,7 @@ else()
   add_library(boost_stacktrace INTERFACE)
   set(__scope INTERFACE)
 endif()
+unset(__import_std)
 
 target_include_directories(boost_stacktrace ${__scope} "${CMAKE_CURRENT_LIST_DIR}/include")
 add_library(Boost::stacktrace ALIAS boost_stacktrace)
@@ -182,7 +202,7 @@ target_link_libraries(boost_stacktrace ${__scope} Boost::stacktrace_${__default_
 
 # Boost::stacktrace_from_exception is never the default
 if(_enable_non_noop_backend)
-  stacktrace_add_library(from_exception ${BOOST_STACKTRACE_ENABLE_FROM_EXCEPTION} Boost::stacktrace_dump "${CMAKE_DL_LIBS}" "" FALSE)
+  stacktrace_add_library(from_exception ${BOOST_STACKTRACE_ENABLE_FROM_EXCEPTION} Boost::stacktrace_dump "${CMAKE_DL_LIBS}" "" FALSE FALSE)
 endif()
 unset(_enable_non_noop_backend)
 

diff --git a/include/boost/stacktrace/detail/addr_base.hpp b/include/boost/stacktrace/detail/addr_base.hpp
@@ -12,12 +12,12 @@
 #   pragma once
 #endif
 
-#if !defined(BOOST_STACKTRACE_INTERFACE_UNIT)
+#if !defined(BOOST_STACKTRACE_INTERFACE_UNIT) && !defined(BOOST_STACKTRACE_USE_STD_MODULE)
 #include <fstream>
 #include <sstream>
 #include <cstdint>
 #include <cstdlib>
-#endif // !defined(BOOST_STACKTRACE_INTERFACE_UNIT)
+#endif // !defined(BOOST_STACKTRACE_INTERFACE_UNIT) && !defined(BOOST_STACKTRACE_USE_STD_MODULE)
 
 namespace boost { namespace stacktrace { namespace detail {
 

diff --git a/include/boost/stacktrace/detail/frame_decl.hpp b/include/boost/stacktrace/detail/frame_decl.hpp
@@ -15,9 +15,9 @@
 #   pragma once
 #endif
 
-#if !defined(BOOST_STACKTRACE_INTERFACE_UNIT)
+#if !defined(BOOST_STACKTRACE_INTERFACE_UNIT) && !defined(BOOST_STACKTRACE_USE_STD_MODULE)
 #include <string>
-#endif // !defined(BOOST_STACKTRACE_INTERFACE_UNIT)
+#endif // !defined(BOOST_STACKTRACE_INTERFACE_UNIT) && !defined(BOOST_STACKTRACE_USE_STD_MODULE)
 
 #if !defined(BOOST_USE_MODULES)
 #include <boost/stacktrace/safe_dump_to.hpp>

diff --git a/include/boost/stacktrace/detail/frame_unwind.ipp b/include/boost/stacktrace/detail/frame_unwind.ipp
@@ -15,7 +15,9 @@
 #if !defined(BOOST_STACKTRACE_INTERFACE_UNIT)
 #include <boost/core/demangle.hpp>
 
+#if !defined(BOOST_STACKTRACE_USE_STD_MODULE)
 #include <cstdio>
+#endif // !defined(BOOST_STACKTRACE_USE_STD_MODULE)
 #endif // !defined(BOOST_STACKTRACE_INTERFACE_UNIT)
 
 #include <boost/stacktrace/frame.hpp>

diff --git a/include/boost/stacktrace/detail/to_dec_array.hpp b/include/boost/stacktrace/detail/to_dec_array.hpp
@@ -12,10 +12,10 @@
 #   pragma once
 #endif
 
-#if !defined(BOOST_STACKTRACE_INTERFACE_UNIT)
+#if !defined(BOOST_STACKTRACE_INTERFACE_UNIT) && !defined(BOOST_STACKTRACE_USE_STD_MODULE)
 #include <array>
 #include <cstddef>  // std::size_t
-#endif // !defined(BOOST_STACKTRACE_INTERFACE_UNIT)
+#endif // !defined(BOOST_STACKTRACE_INTERFACE_UNIT) && !defined(BOOST_STACKTRACE_USE_STD_MODULE)
 
 namespace boost { namespace stacktrace { namespace detail {
 

diff --git a/include/boost/stacktrace/detail/to_hex_array.hpp b/include/boost/stacktrace/detail/to_hex_array.hpp
@@ -12,10 +12,10 @@
 #   pragma once
 #endif
 
-#if !defined(BOOST_STACKTRACE_INTERFACE_UNIT)
+#if !defined(BOOST_STACKTRACE_INTERFACE_UNIT) && !defined(BOOST_STACKTRACE_USE_STD_MODULE)
 #include <array>
 #include <type_traits>
-#endif // !defined(BOOST_STACKTRACE_INTERFACE_UNIT)
+#endif // !defined(BOOST_STACKTRACE_INTERFACE_UNIT) && !defined(BOOST_STACKTRACE_USE_STD_MODULE)
 
 namespace boost { namespace stacktrace { namespace detail {
 

diff --git a/include/boost/stacktrace/detail/void_ptr_cast.hpp b/include/boost/stacktrace/detail/void_ptr_cast.hpp
@@ -13,9 +13,9 @@
 #   pragma once
 #endif
 
-#if !defined(BOOST_STACKTRACE_INTERFACE_UNIT)
+#if !defined(BOOST_STACKTRACE_INTERFACE_UNIT) && !defined(BOOST_STACKTRACE_USE_STD_MODULE)
 #include <type_traits>
-#endif // !defined(BOOST_STACKTRACE_INTERFACE_UNIT)
+#endif // !defined(BOOST_STACKTRACE_INTERFACE_UNIT) && !defined(BOOST_STACKTRACE_USE_STD_MODULE)
 
 #if defined(__GNUC__) && defined(__GNUC_MINOR__) && (__GNUC__ * 100 + __GNUC_MINOR__ > 301)
 #   pragma GCC system_header

diff --git a/include/boost/stacktrace/frame.hpp b/include/boost/stacktrace/frame.hpp
@@ -15,10 +15,10 @@
 #   pragma once
 #endif
 
-#if !defined(BOOST_STACKTRACE_INTERFACE_UNIT)
+#if !defined(BOOST_STACKTRACE_INTERFACE_UNIT) && !defined(BOOST_STACKTRACE_USE_STD_MODULE)
 #include <iosfwd>
 #include <string>
-#endif // !defined(BOOST_STACKTRACE_INTERFACE_UNIT)
+#endif // !defined(BOOST_STACKTRACE_INTERFACE_UNIT) && !defined(BOOST_STACKTRACE_USE_STD_MODULE)
 
 #include <boost/stacktrace/detail/frame_decl.hpp>
 #include <boost/stacktrace/detail/push_options.h>

diff --git a/include/boost/stacktrace/safe_dump_to.hpp b/include/boost/stacktrace/safe_dump_to.hpp
@@ -20,7 +20,10 @@
 #endif
 
 #if !defined(BOOST_STACKTRACE_INTERFACE_UNIT)
+
+#if !defined(BOOST_STACKTRACE_USE_STD_MODULE)
 #include <cstddef>
+#endif // !defined(BOOST_STACKTRACE_USE_STD_MODULE)
 
 #if defined(BOOST_WINDOWS)
 #include <boost/winapi/config.hpp>

diff --git a/include/boost/stacktrace/stacktrace.hpp b/include/boost/stacktrace/stacktrace.hpp
@@ -19,13 +19,15 @@
 #include <boost/core/no_exceptions_support.hpp>
 #include <boost/container_hash/hash_fwd.hpp>
 
+#if !defined(BOOST_STACKTRACE_USE_STD_MODULE)
 #include <iosfwd>
 #include <string>
 #include <vector>
 
 #ifndef BOOST_NO_CXX11_HDR_TYPE_TRAITS
 #   include <type_traits>
 #endif
+#endif // !defined(BOOST_STACKTRACE_USE_STD_MODULE)
 #endif // !defined(BOOST_STACKTRACE_INTERFACE_UNIT)
 
 #include <boost/stacktrace/stacktrace_fwd.hpp>

diff --git a/include/boost/stacktrace/stacktrace_fwd.hpp b/include/boost/stacktrace/stacktrace_fwd.hpp
@@ -11,10 +11,10 @@
 
 #if !defined(BOOST_USE_MODULES) || defined(BOOST_STACKTRACE_INTERFACE_UNIT)
 
-#if !defined(BOOST_STACKTRACE_INTERFACE_UNIT)
+#if !defined(BOOST_STACKTRACE_INTERFACE_UNIT) && !defined(BOOST_STACKTRACE_USE_STD_MODULE)
 #include <cstddef>
 #include <memory>
-#endif // !defined(BOOST_STACKTRACE_INTERFACE_UNIT)
+#endif // !defined(BOOST_STACKTRACE_INTERFACE_UNIT) && !defined(BOOST_STACKTRACE_USE_STD_MODULE)
 
 /// @file stacktrace_fwd.hpp This header contains only forward declarations of
 /// boost::stacktrace::frame, boost::stacktrace::basic_stacktrace, boost::stacktrace::stacktrace

diff --git a/modules/boost_stacktrace_addr2line.cppm b/modules/boost_stacktrace_addr2line.cppm
@@ -18,10 +18,12 @@ module;
 #include <boost/container_hash/hash_fwd.hpp>
 #include <boost/predef.h>
 
+#if !defined(BOOST_STACKTRACE_USE_STD_MODULE)
 #include <vector>
 #include <fstream>
 #include <sstream>
 #include <cxxabi.h>
+#endif
 
 #include <sys/types.h>
 #include <sys/wait.h>
@@ -34,6 +36,10 @@ module;
 
 export module boost.stacktrace.addr2line;
 
+#if defined(BOOST_STACKTRACE_USE_STD_MODULE)
+import std;
+#endif
+
 import boost.stacktrace.dump;
 
 #ifdef __clang__

diff --git a/modules/boost_stacktrace_backtrace.cppm b/modules/boost_stacktrace_backtrace.cppm
@@ -20,10 +20,12 @@ module;
 
 #include <backtrace.h>
 
+#if !defined(BOOST_STACKTRACE_USE_STD_MODULE)
 #include <vector>
 #include <fstream>
 #include <sstream>
 #include <cxxabi.h>
+#endif
 
 #include <dlfcn.h>
 
@@ -32,6 +34,10 @@ module;
 
 export module boost.stacktrace.backtrace;
 
+#if defined(BOOST_STACKTRACE_USE_STD_MODULE)
+import std;
+#endif
+
 import boost.stacktrace.dump;
 
 #ifdef __clang__

diff --git a/modules/boost_stacktrace_basic.cppm b/modules/boost_stacktrace_basic.cppm
@@ -18,10 +18,12 @@ module;
 #include <boost/container_hash/hash_fwd.hpp>
 #include <boost/predef.h>
 
+#if !defined(BOOST_STACKTRACE_USE_STD_MODULE)
 #include <vector>
 #include <fstream>
 #include <sstream>
 #include <cxxabi.h>
+#endif
 
 #include <dlfcn.h>
 
@@ -30,6 +32,10 @@ module;
 
 export module boost.stacktrace.basic;
 
+#if defined(BOOST_STACKTRACE_USE_STD_MODULE)
+import std;
+#endif
+
 import boost.stacktrace.dump;
 
 #ifdef __clang__

diff --git a/modules/boost_stacktrace_dump.cppm b/modules/boost_stacktrace_dump.cppm
@@ -14,16 +14,23 @@ module;
 #include <boost/config.hpp>
 #include <boost/predef.h>
 
+#if !defined(BOOST_STACKTRACE_USE_STD_MODULE)
+#include <stdio.h>
+#endif
+
 #include <fcntl.h>
 #include <unwind.h>
-#include <stdio.h>
 #include <sys/stat.h>
 
 #define BOOST_STACKTRACE_INTERFACE_UNIT
 #define BOOST_STACKTRACE_LINK
 
 export module boost.stacktrace.dump;
 
+#if defined(BOOST_STACKTRACE_USE_STD_MODULE)
+import std;
+#endif
+
 #ifdef __clang__
 #   pragma clang diagnostic ignored "-Winclude-angled-in-module-purview"
 #endif

diff --git a/modules/boost_stacktrace_noop.cppm b/modules/boost_stacktrace_noop.cppm
@@ -11,14 +11,20 @@ module;
 #include <boost/core/no_exceptions_support.hpp>
 #include <boost/container_hash/hash_fwd.hpp>
 
+#if !defined(BOOST_STACKTRACE_USE_STD_MODULE)
 #include <vector>
 #include <memory>
+#endif
 
 #define BOOST_STACKTRACE_INTERFACE_UNIT
 #define BOOST_STACKTRACE_LINK
 
 export module boost.stacktrace.noop;
 
+#if defined(BOOST_STACKTRACE_USE_STD_MODULE)
+import std;
+#endif
+
 #ifdef __clang__
 #   pragma clang diagnostic ignored "-Winclude-angled-in-module-purview"
 #endif

diff --git a/modules/samples/usage_sample_from_exception.cpp b/modules/samples/usage_sample_from_exception.cpp
@@ -6,7 +6,7 @@
 // http://www.boost.org/LICENSE_1_0.txt)
 
 #include <iostream>
-#include <stdexcept>
+#include <map>
 
 #include <boost/config.hpp>
 
@@ -15,7 +15,8 @@
 namespace {
 
 BOOST_NOINLINE void foo() {
-    throw std::logic_error{"Foo"};
+    std::map<int, int> m;
+    std::ignore = m.at(1);
 }
 
 BOOST_NOINLINE void bar() {