http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48882
Summary: ?: ternary operator fails in certain contexts -
compile error
Product: gcc
Version: 4.7.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: adele.schmidtham...@yahoo.de
#include<algorithm> // std::max std::min
#include<iostream>
int main() {
int a = 1000;
int b = 2000;
bool even = true;
const int& (*fp)(const int&, const int&);
fp = even ? std::max<int> : std::min<int>; /* does not compile! */
std::cout << fp(a,b) << std::endl;
}
Error message: insufficient contextual information to determine type
however
if(even) fp = std::max<int>;
else fp = std::min<int>;
works as expected:
Output of compilation:
Es werden eingebaute Spezifikationen verwendet.
COLLECT_GCC=/home/me/programme/gcc47/bin/g++
COLLECT_LTO_WRAPPER=/home/me/programme/gcc47/libexec/gcc/i686-pc-linux-gnu/4.7.0/lto-wrapper
Ziel: i686-pc-linux-gnu
Konfiguriert mit: ./configure --prefix=/home/me/programme/gcc47
Thread-Modell: posix
gcc-Version 4.7.0 20110430 (experimental) (GCC)
COLLECT_GCC_OPTIONS='-v' '-std=c++0x' '-Wall' '-save-temps' '-shared-libgcc'
'-mtune=generic' '-march=pentiumpro'
/home/me/programme/gcc47/libexec/gcc/i686-pc-linux-gnu/4.7.0/cc1plus -E -quiet
-v -D_GNU_SOURCE bug1.cpp -mtune=generic -march=pentiumpro -std=c++0x -Wall
-fpch-preprocess -o bug1.ii
nicht vorhandenes Verzeichnis
»/home/me/programme/gcc47/lib/gcc/i686-pc-linux-gnu/4.7.0/../../../../i686-pc-linux-gnu/include«
wird ignoriert
#include "..." - Suche beginnt hier:
#include <...> - Suche beginnt hier:
/home/me/programme/gcc47/lib/gcc/i686-pc-linux-gnu/4.7.0/../../../../include/c++/4.7.0
/home/me/programme/gcc47/lib/gcc/i686-pc-linux-gnu/4.7.0/../../../../include/c++/4.7.0/i686-pc-linux-gnu
/home/me/programme/gcc47/lib/gcc/i686-pc-linux-gnu/4.7.0/../../../../include/c++/4.7.0/backward
/home/me/programme/gcc47/lib/gcc/i686-pc-linux-gnu/4.7.0/include
/usr/local/include
/home/me/programme/gcc47/include
/home/me/programme/gcc47/lib/gcc/i686-pc-linux-gnu/4.7.0/include-fixed
/usr/include
Ende der Suchliste.
COLLECT_GCC_OPTIONS='-v' '-std=c++0x' '-Wall' '-save-temps' '-shared-libgcc'
'-mtune=generic' '-march=pentiumpro'
/home/me/programme/gcc47/libexec/gcc/i686-pc-linux-gnu/4.7.0/cc1plus
-fpreprocessed bug1.ii -quiet -dumpbase bug1.cpp -mtune=generic
-march=pentiumpro -auxbase bug1 -Wall -std=c++0x -version -o bug1.s
GNU C++ (GCC) Version 4.7.0 20110430 (experimental) (i686-pc-linux-gnu)
kompiliert von GNU-C-Version 4.7.0 20110430 (experimental), GMP-Version
5.0.1, MPFR-Version 3.0.0-p3, MPC-Version 0.8.2.
GGC-Heuristik: --param ggc-min-expand=30 --param ggc-min-heapsize=4096
GNU C++ (GCC) Version 4.7.0 20110430 (experimental) (i686-pc-linux-gnu)
kompiliert von GNU-C-Version 4.7.0 20110430 (experimental), GMP-Version
5.0.1, MPFR-Version 3.0.0-p3, MPC-Version 0.8.2.
GGC-Heuristik: --param ggc-min-expand=30 --param ggc-min-heapsize=4096
Compiler executable checksum: c95befb475332395eb1695ad61c47f68
bug1.cpp: In Funktion »int main()«:
bug1.cpp:19:38: Fehler: insufficient contextual information to determine type
bug1.cpp:19:38: Fehler: insufficient contextual information to determine type
