• kdevel (24/24) Jan 23 2021 In § 19.18.7 [1] it is said that
• Mike Parker (5/12) Jan 23 2021 I assume because of mangling. The outer function is mangled into
• Mike Parker (3/11) Jan 23 2021 And also that nested functions needs to reference the stack of

kdevel <kdevel vogtner.de> writes:

In § 19.18.7 [1] it is said that

    Nested functions always have the D function linkage type.

Why and for what application is that important? As this example

~~~znested.d
void foo () { }
unittest {
    void nested () { }
    import std.stdio;
    writeln (typeof (nested).stringof);
    writeln (typeof (&nested).stringof);
    writeln (typeof (foo).stringof);
    writeln (typeof (&foo).stringof);
}
~~~

    $ dmd -unittest -checkaction=context -main -run znested.d
    pure nothrow  nogc  safe void()
    void delegate() pure nothrow  nogc  safe
    void()
    void function()
    1 unittests passed

shows from the object with D function linkage type named "nested"
a delegate is created as soon as its address is taken. (function
pointers are only generated from static nested functions)

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

Mike Parker <aldacron gmail.com> writes:

On Saturday, 23 January 2021 at 20:37:49 UTC, kdevel wrote:
 In § 19.18.7 [1] it is said that

    Nested functions always have the D function linkage type.

 Why and for what application is that important?

I assume because of mangling. The outer function is mangled into 
the nested function's name.


 shows from the object with D function linkage type named 
 "nested"
 a delegate is created as soon as its address is taken. (function
 pointers are only generated from static nested functions)

Yes. That's documented here:

https://dlang.org/spec/function.html#closures

Mike Parker <aldacron gmail.com> writes:

On Sunday, 24 January 2021 at 02:30:37 UTC, Mike Parker wrote:
 On Saturday, 23 January 2021 at 20:37:49 UTC, kdevel wrote:
 In § 19.18.7 [1] it is said that

    Nested functions always have the D function linkage type.

 Why and for what application is that important?

 I assume because of mangling. The outer function is mangled 
 into the nested function's name.

And also that nested functions needs to reference the stack of 
the enclosing function.