[swift-evolution] URL Literals

[Georgios Moschovitis]

> As a bonus (IMHO, anyway) adding `@constexpr` would lay the groundwork for adding `@pure` later on, both in 

Could that be just `@const` (since that keyword is not reserved yet)? Or something else? 

It bugs be that the `constexpr` keyword is hard to pronounce (and lacks a separator between the two constituent words). Even just `const`.

-g.