gcc4.8

If I read the C++ ISO specification (sections 5.8.2 and 5.8.3) right, the right-shift of negative signed types is implementation specific and the left-shift undefined behaviour. Therefore I would like to find shift operations on signed types in our legacy source code which we compile with g++ 4.8.2. Unfortunately, I couldn't find such an option in the manual . I can for example compile this code with "g++ -Wall -Wextra -pedantic" without a warning: int si = -1; int left = si << 1; // -2 (multiplication by 2, sign is preserved) int right = si >> 1; // -1 (no change, only 1s) Can anyone tell me

I have just dist-upgraded a Debian Weezy machine to run gcc-4.8 from gcc-4.7. Previously the build environment was sane and was compiling normally. Now it gives the following linker errors, with any program (even a trivial hello world): /usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 0 has invalid symbol index 11 /usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 1 has invalid symbol index 12 /usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 2 has invalid symbol index 2 /usr/bin/ld: /usr

This question already has an answer here: Is gcc 4.8 or earlier buggy about regular expressions? 3 answers I tried to use C++11's regular expression but failed even in trivial examples. From the outside, it seems to only compare the strings, for example: std::regex_match(std::string{""}, std::regex{"a?"}) // false (???) std::regex_match(std::string{"a?"}, std::regex{"a?"}) // true (???) In contrast, the Boost's regexp library behaves as I would have expected: boost::regex_match(std::string{""}, boost::regex{"a?"}) // true (OK) boost::regex_match(std::string{"a?"}, boost::regex{"a?"}) // false