US102 13.1 p4.1 Allow non-type template parameters of floating-point type P1714

[wg21bot]

If it is decided not to use == to define equivalence of class-type non-type template arguments (just as it is not used for references and pointers to members), some of the uncertainty surrounding non-type template parameters of floating-point type will no longer pertain, whereas the (very real) availability of undesirable workarounds involving std::bit_cast(-0.f) will persist.

Proposed change:
Apply P1714R1 (as already approved by EWG and CWG).

[jfbastien]

See cplusplus/papers#480

[jfbastien]

Will explore with #113

[davidstone]

EWG voted to accept US102 with modification by allowing floating-point non-type template parameters for c++20

[jensmaurer]

CWG in Belfast: Accepted with modification. See paper P1907R1.