Dear all,

Here follows a patch that removes implicit type casts in std::complex.

*Description:* The current implementation of `complex<_Tp>` assumes that
`int, double, long double` are explicitly convertible to `_Tp`. Moreover,
it also assumes that:

1. `int` is implicitly convertible to `_Tp`, e.g., when using
`complex<_Tp>(1)`.
2. `long double` can be attributed to a `_Tp` variable, e.g., when using
`const _Tp __pi_2 = 1.5707963267948966192313216916397514L`.

This patch transforms the implicit casts (1) and (2) into explicit type
casts. As a result, `std::complex` is now able to support more types. One
example is the type `Eigen::Half` from
https://eigen.tuxfamily.org/dox-devel/Half_8h_source.html which does not
implement implicit type conversions.

*ChangeLog:*
libstdc++-v3/ChangeLog:

        * include/std/complex:

*Patch:* fix_complex.diff. (Also at
https://github.com/gcc-mirror/gcc/pull/84)

*OBS:* I didn't find a good reason for adding new tests or test results
here since this is really a small upgrade (in my view) to std::complex.

Sincerely,
  Weslley

-- 
Weslley S. Pereira