• number (25/25) Apr 08 2018 the write() shows a 'null' if the struct has a function/method.
• Paul Backus (6/31) Apr 08 2018 S2 is a nested struct [1], which means it has a hidden pointer
• number (4/11) Apr 09 2018 Aha, its the nesting. And if i access the outer scope in the

number <putimalitze gmx.de> writes:

the write() shows a 'null' if the struct has a function/method. 
why is that?
```
import std.stdio;

void main()
{
	struct S
	{
		int i;
	}
	S s;
	writeln(s);                // S(0)
	writeln(typeid(s).sizeof); // 8
	
	struct S2
	{
		int i;
		this(this){}
	}
	S2 s2;
	import std.conv: to;
	writeln(s2);                // S2(0, null)
	writeln(typeid(s2).sizeof); // 8
}
```

Paul Backus <snarwin gmail.com> writes:

On Sunday, 8 April 2018 at 15:04:49 UTC, number wrote:
 the write() shows a 'null' if the struct has a function/method. 
 why is that?
 ```
 import std.stdio;

 void main()
 {
 	struct S
 	{
 		int i;
 	}
 	S s;
 	writeln(s);                // S(0)
 	writeln(typeid(s).sizeof); // 8
 	
 	struct S2
 	{
 		int i;
 		this(this){}
 	}
 	S2 s2;
 	import std.conv: to;
 	writeln(s2);                // S2(0, null)
 	writeln(typeid(s2).sizeof); // 8
 }
 ```

S2 is a nested struct [1], which means it has a hidden pointer 
field that's used to access its enclosing scope. If you change 
the definition to `static struct S2`, you'll get the same output 
for both structs.

[1] https://dlang.org/spec/struct.html#nested

number <putimalitze gmx.de> writes:

On Sunday, 8 April 2018 at 15:51:05 UTC, Paul Backus wrote:
 On Sunday, 8 April 2018 at 15:04:49 UTC, number wrote:
 	writeln(s2);                // S2(0, null)

 S2 is a nested struct [1], which means it has a hidden pointer 
 field that's used to access its enclosing scope. If you change 
 the definition to `static struct S2`, you'll get the same 
 output for both structs.

 [1] https://dlang.org/spec/struct.html#nested

Aha, its the nesting. And if i access the outer scope in the 
function its not null anymore.
Thank you!