https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97091
Bug ID: 97091 Summary: Demangling the name of the type of a lambda accepting variadic auto parameters fails Product: gcc Version: 11.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: libstdc++ Assignee: unassigned at gcc dot gnu.org Reporter: dominik.muth at gmx dot de Target Milestone: --- Demangling the mangled name of [](auto...){} fails with gcc 5, 8, 9, 10, and 11. It works with gcc 6 and 7, however the mangled name is different, see output below. The demangled name main::{lambda(auto:1, ...)#1} looks wrong to me. Should it be main::{lambda(auto:1...)#1} instead? Here is a fairly minimal example to reproduce the bug: // https://wandbox.org/permlink/FVonGE60X1Xi651E #include <iostream> #include <cxxabi.h> using namespace std; template <typename T> static string nametype(T v) { return typeid(decltype(v)).name(); } template <typename T> static string strtype(T v) { return abi::__cxa_demangle(nametype(v).c_str(), nullptr, nullptr, nullptr); } template <typename T> static void puttype(T v) { cout << nametype(v) << endl; cout << "-> " << strtype(v) << endl; } int main() { cout << __GNUC__ << "." << __GNUC_MINOR__ << "." << __GNUC_PATCHLEVEL__ << " " << __GLIBCXX__ << endl; puttype([](auto...){}); } /* output: 5.5.0 20171010 Z4mainEUlT_zE_ terminate called after throwing an instance of 'std::logic_error' what(): basic_string::_M_construct null not valid 6.3.0 20161221 Z4mainEUlT_zE_ -> main::{lambda(auto:1, ...)#1} 7.3.0 20180125 Z4mainEUlT_zE_ -> main::{lambda(auto:1, ...)#1} 8.3.0 20190222 Z4mainEUlDpT_E0_ terminate called after throwing an instance of 'std::logic_error' what(): basic_string::_M_construct null not valid 9.3.0 20200312 Z4mainEUlDpT_E0_ terminate called after throwing an instance of 'std::logic_error' what(): basic_string::_M_construct null not valid 10.1.0 20200507 Z4mainEUlDpT_E_ terminate called after throwing an instance of 'std::logic_error' what(): basic_string::_M_construct null not valid 11.0.0 20200915 Z4mainEUlDpT_E_ terminate called after throwing an instance of 'std::logic_error' what(): basic_string::_M_construct null not valid */