CodePagesNet
commented
1 year ago Great to see the note that std lib modules are ready for production use (as of VS2022 17.5, MSVC only). Does that mean that the statement shown here in the documentation about not using preview releases in production code, should be removed? https://learn.microsoft.com/en-us/cpp/cpp/tutorial-import-stl-named-module?view=msvc-170#prerequisites
:page_facing_up: Documentation
stdandstd.compat:construction: Status
We've reported the following compiler bugs; this issue is for tracking the status of these compiler bugs and removing workarounds/adding test coverage as compiler fixes are released.
As
/clrC++20 support is a work in progress, we are not yet testing Standard Library Header Units under/clr.:x: Clang
:bug: EDG (IntelliSense Front-End)
:beetle: Active, UCRT
static inlinefunctions cannot be called when using modules":lady_beetle: Active, C1XX (MSVC Front-End)
3661
stdmodule to export too much stuff.pair(piecewise_construct_t, tuple, tuple)"std::formatin a module requires including<format>header in .cpp files using that module"std::stacktrace":grey_question: Possible Improvements (C1XX/MSBuild)
import std.compat;,std::printf, orstd::cout"import std;is seen, butstd.ifc/std.objneed to be built"import std;andimport std.compat;":hammer_and_wrench: Upcoming Improvements (C1XX)
:adhesive_bandage: Permanent Workarounds
std::projected::operator*()error LNK2019: unresolved external symbol"abort().:heart_eyes_cat: Fixed, Workaround Removed
'std::pointer_traits<_Voidptr>': more than one partial specialization matches the template argument list"__pragma(warning(disable : 4996))doesn't take effect"'std::char_traits'"std::_Yarn<char>::operator=(char const *)already defined"std::optional,c1xx!FindConversionFunctions()assertion failed:PF_ISSET(ParsingClassTemplateDefn)"std::variant,c1xx!Module::InterfaceReader::materialize_function()assertion failed"'std::ranges::operator ==': a trailingrequiresclause is only allowed on a templated function"/headerUnit:angleICEs"queue'sfriend bool operator=="/headerUnit:angle vector=vector.ifcheader-units.jsonvia/sourceDependencies:directivesand/translateInclude/exportHeader /headerName:angle algorithm type_traits vector_Nontrivial_dummy_type's constructor"type_info's equality operator"<format>as a header unit"_CrtGetAllocHookemits warning C5106: macro redefined with different parameter names"convertible_toconstrains a constructor"<ranges>compiler assertion:previous_element == tokenInputStack.TopOfStack(), aliastemplates.cpp 1010"template <int = 0>tovformat()emits warnings C4265 and C4365"#pragma warningdoesn't always suppress warnings in templates"/scanDependenciesgenerates incorrect"logical-name"in JSON output"fatal error C1116: unrecoverable error importing module, with<concepts>"fatal error C1116: unrecoverable error importing module ''"error C2672: 'count_if': no matching overloaded function found"chrono::daysemits bogus error C2131"<chrono>emits fatal error C1116: unrecoverable error importing header unit'<chrono>'"std.ixxemits fatal error C1011: cannot locate standard module interface"extern "C"function declarations takingextern "C"types emit bogus error LNK2019: unresolved external symbol"extern "C"function mentioning entity with module linkage is being marked with module linkage"Module::InterfaceReader::materialize_function<Module::helpers::MemberBuilder>()"construct_atSFINAE causes Modules bogus error C2660: 'operator new': function does not take 3 arguments"<codecvt>: fatal error C1001: Internal compiler error.<any>: error C2679: binary'!=': no operator found which takes a right-hand operand of type'const type_info'(or there is no acceptable conversion)<memory>: error C2679: binary'==': no operator found which takes a right-hand operand of type'const type_info'(or there is no acceptable conversion)<functional>: error C2027: use of undefined type'type_info'<typeinfo>: error C2872:'type_info': ambiguous symbol<typeindex>: error C2440: 'initializing': cannot convert from 'initializer list' to'std::type_index'<regex>: Assertion failed:Nerrors > 0, fileD:\msvc\src\vctools\Compiler\CxxFE\sl\p1\c\trees.c/d1ifcInlineFunctionsasserts(bits::rep(typeEncoding.basicEncoding_) & 0x0000000F) != 0forprintf(_Format, ...)"<expected>ICEs withAssertion failed: IsInClassDefn()"'_Iterator_base12': the symbol to the left of a'::'must be a type"operator&"inline constexprvariables forranges::viewsemiterror LNK2019: unresolved external symbol"'memcpy_s'because it has internal linkage"extern "C++"is directly applied to a class with a static member function"std::views::join_with"variantwith inheriting constructors"chunk_viewof input iterators"inserted, file template.cpp, line 10275"IsInClassDefn() && (region->owner == SU_TAG), file reader.cpp, line 2592"3112 DevCom-10154236 "
<fstream>: Importing as a header unit leads to error C2079: undefined class'std::basic_ofstream<char,std::char_traits<char>>'"destroy_at()emits bogus error C2131: expression did not evaluate to a constant"iota_viewemits bogus error C7608: atomic constraint should be a constant expression"constexpr vector::resize()ICE"ranges::iterator_tcauses ICE"3287 VSO-1706387 "
<atomic>: Building a header unit with/ZIemits warning C5260"source_location::column()misbehaves in user headers"3330 DevCom-10247495 VSO-1714748 "MSVC forces us to export some internal enumeration functions for working with C++ modules"
3333 VSO-1715231 "Standard Library Modules: Bogus error C2504:
'std::filesystem::_Dir_enum_impl': base class undefined"charconvgives wrong result"using namespace std::chrono;for UDLs emits bogus error C3688: invalid literal suffix"/analyzeICE"osyncstreammove assignment emits bogus error C3083:'basic_ostream<char,std::char_traits<char> >': the symbol to the left of a'::'must be a type"sort()emits bogus error C2065:'_Atomic_counter_t': undeclared identifier"chronoformatting emits bogus error C3861:'_Fill_tm': identifier not found"'#include <meow>'in the purview of module'std'appears erroneous"tuplechanges"<format>causes C4296 warning that need to be suppressed every time" (with header units)static constexprdata members"std::expectederror C2280 attempting to reference a deleted function"std::views::iotain member function in module causes ICE"std::views::repeatin member functions gives bogus error about lack ofcompareheader"'...': there are no parameter packs available to expand module"numeric_limits"ctype<char>::table_sizeshould be a compile-time constant"std::mdspanis unusable with C++20 modules"std::basic_string_viewsymbols""<chrono>year_month_weekdayandyear_month_weekday_lastemit bogus error C2131: expression did not evaluate to a constant"day{31}initializers emits 'not yet implemented' internal compiler error"extern "C++"doesn't avoid all problems when mixing includes and imports"extern "C++"interferes with ADL"std::filesystem::path::generic_string()in a module unit"'std'when constructing and exporting astd::chrono::zoned_timeobject"chrono::time_pointformatting emits bogus error C3861:'_Fill_tm': identifier not found"utc_clock::now()emits fatal error C1116: unrecoverable error importing module'std'."'std'. Specialization of'std::invoke_result_t'with arguments'_Fn, _Ty...'"std::views::zipwithstd::views::iotain C++20 module results in C1001 Internal compiler error":building_construction: Building Deduplicated Header Units
Here's the part of our Python-powered test harness that builds "deduplicated" header units by topologically sorting them:
https://github.com/microsoft/STL/blob/ef62d3fa0b8e4e2406b9bb74e916e1ca8a1df802/tests/std/tests/P1502R1_standard_library_header_units/custom_format.py#L56-L109
With a bit of work, this can be extracted into a standalone Python script. (With significantly more work, it could be converted into CMake.)