Re: [boost] [Safe Numerics] Review

Subject: Re: [boost] [Safe Numerics] Review
From: Peter Dimov (lists_at_[hidden])
Date: 2017-03-12 14:54:06

John Maddock wrote:

> 5) What is the purpose of class safe_literal? constepxr initialization 
> seems to work just fine without it?

The idea, I believe, is that if you have

    safe_signed_range<0, 100> x;

and then you do

    auto y = x * safe_signed_literal<2>();

you get safe_signed_range<0, 200> as the type of y. This could probably be 
made less elaborate with a user-defined literal, for example

    auto y = x * 2_sf;

or something like that.

Since x is not constexpr, it's not possible (I think) to achieve this result 
without using a separate literal type to hold the compile-time constant 2.