Re: [boost] [Multiprecision] Does MP use references internally?

Subject: Re: [boost] [Multiprecision] Does MP use references internally?
From: John Maddock (john_at_[hidden])
Date: 2013-06-21 07:56:53

> Nearly all operators, besides assigning and dereferencing ones, are 
> supposed to return by value.
> Changing that, even with the “innocuous” (unary)+, is surprising.

This came up in review actually with no good solution - the main issue 
(apart from no one ever using unary + anyway) is that pretty much every 
numeric-class type ever written has done it that way.

However... in the C++11 world I can think of one legitimate use case that's 
broken by this - and that's when you have user-defined literals:

auto x = +1234_my_suffix;

which results in a dangling-reference-to-temporary.  So I'll change this 
shortly,

Regards, John.