https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118196
Bug ID: 118196
Summary: The assignment operator for std::generator does not
return, so generators cannot be reassigned
Product: gcc
Version: 14.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: libstdc++
Assignee: unassigned at gcc dot gnu.org
Reporter: florintulba at yahoo dot com
Target Milestone: ---
Created attachment 59966
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=59966&action=edit
archived version of 'test.ii' from -save-temps
The program from below crashes when reassigning the generator 'g =
iotaGen(5);':
"
Generator created!
/usr/include/c++/14/generator:713:7: runtime error: execution reached the end
of a value-returning function without returning a value
"
Expected output:
"
Generator created!
Same generator reassigned successfully!
"
test.cpp:
```cpp
#include <generator>
#include <print>
std::generator<int> iotaGen(int end) {
for (int x{}; x < end; ++x)
co_yield x;
}
int main() {
auto g{iotaGen(10)};
std::println("Generator created!");
g = iotaGen(5);
std::println("Same generator reassigned successfully!");
return 0;
}
```
After adding "return *this;" at the end of the "generator&
generator::operator=(generator)" into the <generator> header and saving the
file as "generator" next to "test.cpp" and changing the include to '#include
"generator"', the program compiles and runs fine.
The used command was:
g++-14 -std=c++23 -D_GLIBCXX_ASSERTIONS -D_GLIBCXX_DEBUG -Wall -Wextra
-fno-strict-aliasing -fwrapv -fno-aggressive-loop-optimizations
-fsanitize=undefined -save-temps -o ./build/test test.cpp && ./build/test
Output of 'g++-14 -v':
"
Using built-in specs.
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-linux-gnu/14/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none:amdgcn-amdhsa
OFFLOAD_TARGET_DEFAULT=1
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu
14.2.0-4ubuntu2~24.04' --with-bugurl=file:///usr/share/doc/gcc-14/README.Bugs
--enable-languages=c,ada,c++,go,d,fortran,objc,obj-c++,m2,rust --prefix=/usr
--with-gcc-major-version-only --program-suffix=-14
--program-prefix=x86_64-linux-gnu- --enable-shared --enable-linker-build-id
--libexecdir=/usr/libexec --without-included-gettext --enable-threads=posix
--libdir=/usr/lib --enable-nls --enable-bootstrap --enable-clocale=gnu
--enable-libstdcxx-debug --enable-libstdcxx-time=yes
--with-default-libstdcxx-abi=new --enable-libstdcxx-backtrace
--enable-gnu-unique-object --disable-vtable-verify --enable-plugin
--enable-default-pie --with-system-zlib --enable-libphobos-checking=release
--with-target-system-zlib=auto --enable-objc-gc=auto --enable-multiarch
--disable-werror --enable-cet --with-arch-32=i686 --with-abi=m64
--with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic
--enable-offload-targets=nvptx-none=/build/gcc-14-ig5ci0/gcc-14-14.2.0/debian/tmp-nvptx/usr,amdgcn-amdhsa=/build/gcc-14-ig5ci0/gcc-14-14.2.0/debian/tmp-gcn/usr
--enable-offload-defaulted --without-cuda-driver --enable-checking=release
--build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
--with-build-config=bootstrap-lto-lean --enable-link-serialization=2
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 14.2.0 (Ubuntu 14.2.0-4ubuntu2~24.04)
"
The generated "test.ii" is attached as 'tbz' archive.
