• kdevel (52/52) May 18 2019 Today I stumbled over this error:
• rikki cattermole (32/32) May 18 2019 Works:

kdevel <kdevel vogtner.de> writes:

Today I stumbled over this error:

elsestaticif.d
```
import std.stdio;

void insert () ()
{
    // some code
}

void insert (T, Args ...) (T x, Args args)
{
    static if (T.stringof == "int") {{
       `int`.writeln;
    }}
    else if (T.stringof == "bool") {{ // ← "static" is missing here
       `bool`.writeln;
    }}
    else static if (T.stringof == "string") {{
       `string`.writeln;
    }}
    else {{
       static assert (false);
    }}
    return insert (args);
}

void main ()
{
    insert (1, true, "string");
}
```

$ dmd elsestaticif
elsestaticif.d(20): Error: static assert:  false is false
elsestaticif.d(22):        instantiated from here: insert!(bool, 
string)
elsestaticif.d(27):        instantiated from here: insert!(int, 
bool, string)

What confuses me is that D allows non-static else mixed with 
static else if clauses. I found this bug:

    https://issues.dlang.org/show_bug.cgi?id=1053
    Issue 1053 - Make 'static else if' or 'static if (...) {...} 
else if' work

which states:

   On the other hand, I'm pretty sure

     static if (foo) { }
     else if (bar) { }

    is an error currently, so it would be nice if that were just 
taken to be a
    "static else if".  There isn't a "static else {}" so why 
should we have to
    repeat the "static" on an "else if"?  One "static" should be 
enough.

That sounds reasonable. Is there any further discussion on this 
problem?

rikki cattermole <rikki cattermole.co.nz> writes:

Works:

---
import std.stdio;

void main()
{
     func!true(false);
     func!false(false);
     func!false(true);
}

void func(bool A)(bool b) {
     static if (A) {
         writeln("a");
     } else if (b) {
     	writeln("b");
     } else {
      	writeln("c");
     }
}
---

This works because that static if + if + else actually is:

---
static if (A) {
	...
} else {
	if (B) {
		...
	} else {
		...
	}
}
---

This works as intended.