Why exe size change if import entire std or just writeln?

[Marcone]

import std.stdio : writeln;

void main(){
	writeln("Bom dia");
}


Size exe file: 258 KB

--------------------------------------------------------------

import std;

void main(){
	writeln("Bom dia");
}

Size exe file: 595 KB



If dependencies are resolved at compile time, why does the 
compiler include extra stuff?