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operator== (strong_order, strong_order) missing from p0768

From: Wesley Shillingford <wezrule_at_[hidden]>
Date: Sat, 4 Jan 2020 14:45:51 +0000
Dear all

First time reporting something, and no idea if this is the appropriate way to do it.

I was playing around with the three-way comparison (spaceship) operator and was surprised when this failed to compile with MSVC:

int x{2};
int y{2};
auto s = x <=> y;
s == std::strong_ordering::equal; // compile failure

VC++ does not define the overload in <compare> for:
operator==(strong_ordering, strong_ordering);

I checked the standard library document and it is not defined, so VC++ is within its right to ignore it and be confirming:

However, gcc does define it:

So this compiles with gcc and not MSVC:

I wonder if it should be added as an alternative to comparing with 0, gcc (libstdc++) saw value in adding it and it would be good to not have yet more inconsistencies in c++ implementations.


Received on 2020-01-04 08:48:22