[Bug c++/39056] [4.4 regression] [c++0x] ICE with invalid initializer list for complex variable

[bkoz at gcc dot gnu dot org]

------- Comment #5 from bkoz at gcc dot gnu dot org  2009-02-03 23:47 -------
> Benjamin, does you have an opinion about initializer-lists and complex?  I
> guess the library complex class will accept { real, imag } naturally because it
> has a suitable constructor.

It would be great if this stuff matched for C/C++. 

#include <complex>

std::complex<double> z1{1.1, 2.2};
std::complex<double> z2{3.3};
std::complex<double> z3{ };

all work with -std=gnu++0x, but not with -std=c++98. So, direct list init works
for C++ std::complex.

All forms of copy-list init fail for std::complex though.

std::complex<double> z4 = {1.1, 2.2};
std::complex<double> z5 = {3.3};
std::complex<double> z6 = { };

complex_init.cc:9: error: call of overloaded ‘complex(<brace-enclosed
initializer list>)Â’ is ambiguous
/mnt/share/bld/gcc/x86_64-unknown-linux-gnu/libstdc++-v3/include/complex:1174:
note: candidates are: std::complex<double>::complex(const std::complex<float>&)
/mnt/share/bld/gcc/x86_64-unknown-linux-gnu/libstdc++-v3/include/complex:1162:
note:                 std::complex<double>::complex(const
std::complex<double>&)

There seems to be some inconsistency in the way this is defined, will bring up
on libstdc++-ml/LWG. 

The original testcase:
__complex__ int i({0});

fails in the C++ version:

std::complex<double> i({0});

So that part is consistent.

-benjamin


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39056