About string and int spliced together.

[zoujiaqing]

Now dlang string processing is complex, like this:

```D
import std.stdio;
import std.conv;

void main()
{
     string name = "Brian";
     uint age = 18;

     string text = "My name is " ~ name ~ " and my age is " ~ 
age.to!string ~ ".";

     writeln(text);
}
```

Type should be automatically converted to string!

It should be:

```D
import std.stdio;

void main()
{
     string name = "Brian";
     uint age = 18;

     string text = "My name is " ~ name ~ " and my age is " ~ age 
~ ".";

     writeln(text);
}
```

Like java:
```D
String name = "Brian";
int age = 18;

System.out.println("My name is " + name + " and my age is " + age 
+ ".");
```