https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92509
Bug ID: 92509
Summary: auto deduction on different types does not emit
diagnostic message
Product: gcc
Version: 9.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: g...@nicholas-schwab.de
Target Milestone: ---
Created attachment 47264
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=47264&action=edit
Preprocessed file on which the error occurs.
By the standard, "if the type that replaces the placeholder type is not the
same in each deduction, the program is ill-formed." Hence the declaration
auto i = 0l, j = 0.0;
should emit a diagnostic message, as it does with an error message. In a more
complex case (prepocessed file attached) this compiles without warning or
error. Was discussed on
https://stackoverflow.com/questions/58855626/mismatched-deduction-of-auto-types-between-different-c-compilers/58856708#58856708
Compiler call:
g++ -v -Wextra -Wall dot.cpp
(preprocessed file created with g++ -save-temps -Wextra -Wall dot.cpp)
Compiler Output:
None
GCC information:
Target: x86_64-pc-linux-gnu
Configured with: /build/gcc/src/gcc/configure --prefix=/usr --libdir=/usr/lib
--libexecdir=/usr/lib --mandir=/usr/share/man --infodir=/usr/share/info
--with-bugurl=https://bugs.archlinux.org/
--enable-languages=c,c++,ada,fortran,go,lto,objc,obj-c++,d --enable-shared
--enable-threads=posix --with-system-zlib --with-isl --enable-__cxa_atexit
--disable-libunwind-exceptions --enable-clocale=gnu --disable-libstdcxx-pch
--disable-libssp --enable-gnu-unique-object --enable-linker-build-id
--enable-lto --enable-plugin --enable-install-libiberty
--with-linker-hash-style=gnu --enable-gnu-indirect-function --enable-multilib
--disable-werror --enable-checking=release --enable-default-pie
--enable-default-ssp --enable-cet=auto gdc_include_dir=/usr/include/dlang/gdc
Thread model: posix
gcc version 9.2.0 (GCC)
