static foreach / How to construct concatenated string?

[MoonlightSentinel]

On Saturday, 7 March 2020 at 16:30:59 UTC, Robert M. Münch wrote:
> Is this possible at all?

You can use an anonymous lambda to build the string in CTFE:

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

struct S {
     int a;
     bool b;
}

import std;

enum string sql = {
     string s = "CREATE TABLE data(";

     static foreach(f; FieldNameTuple!S) {
     	s ~= f ~ ",";
     }

	s ~= ");";
     return s;
} ();

pragma(msg, sql);

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This prints "CREATE TABLE data(a, b);"