user defined literals

[Walter Bright]

On 3/25/2011 8:14 AM, Trass3r wrote:
> Units, I think.
> auto dist = 1km;
> sin(90deg);

One difficulty with the C++0x approach is that the operator"" needed to 
implement it is a global function. Global functions work fine until you wind up 
with two km functions with different purposes, and then things just don't work 
anymore.

In D, you can have user defined literals of the form:

     km!1
     km!"1"
     km(1)

implemented using CTFE. Adding yet another syntax for it seems to be of marginal 
utility.

C++0x needed to add the new syntax because its CTFE ability is minimal, and C++ 
template metaprogramming cannot process strings.