How to add a character literal to a string without ~ operator?

[BoQsc]

I'm looking for more readable standard function to add a 
**character** literal to a **string**.

The `~` operator is clearly not great while reading a source code.
I'm not here to discuss that. I'm looking for a function inside 
standard library.

The function should be straightforward, up to two words.

Here is what I expect from a programming language:

Pseudo example:
```
import std;
void main(){
	string word = hello;
	join(word, 'f', " ", "World");
	writeln(word);   	// output: hellof World
	
}
	
```