https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82347
Bug ID: 82347
Summary: Class Name Injection and Constructor Typenames
Product: gcc
Version: 7.0.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: ahuszagh at gmail dot com
Target Milestone: ---
G++ (including 7.01 and 6.3.0) allowing the following code to compile without
any warning, allowing a type alias of the constructor of a class.
Source File
---
a.cpp
```
#include
#include
#include
int main()
{
using a = typename std::vector::vector;
std::cout << typeid(a).name() << std::endl;
return 0;
}
```
G++ Information
---
Using built-in specs.
COLLECT_GCC=g++-7
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/7/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none
OFFLOAD_TARGET_DEFAULT=1
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu
7-20170407-0ubuntu2' --with-bugurl=file:///usr/share/doc/gcc-7/README.Bugs
--enable-languages=c,ada,c++,go,brig,d,fortran,objc,obj-c++ --prefix=/usr
--with-gcc-major-version-only --program-suffix=-7
--program-prefix=x86_64-linux-gnu- --enable-shared --enable-linker-build-id
--libexecdir=/usr/lib --without-included-gettext --enable-threads=posix
--libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu
--enable-libstdcxx-debug --enable-libstdcxx-time=yes
--with-default-libstdcxx-abi=new --enable-gnu-unique-object
--disable-vtable-verify --enable-libmpx --enable-plugin --enable-default-pie
--with-system-zlib --with-target-system-zlib --enable-objc-gc=auto
--enable-multiarch --disable-werror --with-arch-32=i686 --with-abi=m64
--with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic
--enable-offload-targets=nvptx-none --without-cuda-driver
--enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu
--target=x86_64-linux-gnu
Thread model: posix
gcc version 7.0.1 20170407 (experimental) [trunk revision 246759] (Ubuntu
7-20170407-0ubuntu2)
Complete Command
g++-7 a.cpp
Compiler Output
---
N/A
Preprocessed File
-
(Not applicable?)
Description
---
ISO C++ in [class.qual]/2 states that a nested name specifier for the class
specifies the constructor and not the class, and therefore using `typename
x::x` is therefore not standards compliant. More information can be found on
the StackOverflow post I made on the topic:
https://stackoverflow.com/questions/46412754/class-name-injection-and-constructors
