issue with missing header

[ToiaTech]

Issue 1: Missing <chrono> Header Causes Compilation Failure

File: include/mcut/internal/frontend.h
Line: 410
Severity: Build failure with modern compilers

Description

The frontend.h header uses std::chrono::system_clock::now() but doesn't include <chrono>. This causes compilation failures with clang-cl and other compilers when C++20 is enabled or when include order doesn't bring in chrono transitively.

Current code (line 410):

return std::chrono::duration_cast<std::chrono::nanoseconds>(std::chrono::system_clock::now().time_since_epoch()).count();

Error:

error: no member named 'system_clock' in namespace 'std::chrono'

Fix

Add #include <chrono> to include/mcut/internal/frontend.h after line 54:

#include "mcut/mcut.h"

#include <future>
#include <chrono>  // <-- ADD THIS LINE
#include <map>
#include <memory>
#include <string>

Root Cause

The header relies on transitive inclusion of <chrono> from other headers (like timer.h), but this is fragile and breaks depending on include order and compiler settings.

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Issue 2: Incomplete CMake Install for Shared Libraries on Windows

File: CMakeLists.txt
Lines: 258-276
Severity: Packaging/distribution issue

Description

The CMake install commands for shared libraries are incomplete on Windows. The current code only installs the LIBRARY component, which works for .so files on Unix but doesn't install .dll (RUNTIME) or .lib import libraries (ARCHIVE) on Windows.

Current code (lines 263-266):

install(TARGETS ${mpn_shared_lib_name}
        LIBRARY
        DESTINATION lib/shared
        COMPONENT dynamic_libraries)

Problem

• The current install command only specifies LIBRARY, which is meant for Unix .so files
• This results in the DLL and import lib not being installed, breaking downstream usage

Recommended Fix

Replace lines 258-276 with standard CMake install pattern:

if(MCUT_BUILD_AS_SHARED_LIB)
    install(TARGETS ${mpn_shared_lib_name}
            RUNTIME DESTINATION bin
            LIBRARY DESTINATION lib
            ARCHIVE DESTINATION lib
            COMPONENT dynamic_libraries)
else()
    install(TARGETS ${mpn_static_lib_name}
            ARCHIVE DESTINATION lib
            COMPONENT static_libraries)
endif()

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Suggestion: Simplify Install Destinations

The current install uses non-standard subdirectories (lib/shared, lib/static). Consider using standard CMake conventions:

• Runtime (DLLs): bin/
• Libraries (import libs, static libs, .so files): lib/
• Headers: include/

This aligns with CMake's GNUInstallDirs module and packaging tools like CPack, Conan, and vcpkg.

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Test Configuration

• Compiler: Clang 21.1.0 (clang-cl on Windows)
• CMake: 3.20+
• C++ Standard: C++20
• Build Type: Both Debug and Release affected

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[chitalu]

Thank you. I will commit some update.