Re: string-int[] array

[Dennis Ritchie via Digitalmars-d-learn]

On Sunday, 8 March 2015 at 18:54:43 UTC, Meta wrote:

On Sunday, 8 March 2015 at 18:38:02 UTC, Dennis Ritchie wrote:

On Sunday, 8 March 2015 at 18:18:15 UTC, Baz wrote:

import std.stdio;
import std.typecons;

alias T = Tuple!(string, int);

void main(string[] args)
{
  T[] tarr;
  tarr ~= T("a",65);
  tarr ~= T("b",66);
  writeln(tarr);
}
----

[Tuple!(string, int)("a", 65), Tuple!(string, int)("b", 66)]

Thanks, will do.

It might be better to use std.variant.Algebraic. An array of tuples is wasteful of memory as you only need one or the other.

import std.variant;

alias IntOrStr = Algebraic!(int, string);

IntOrStr[] makeIntOrStrArray(T...)(T vals)
{
        import std.algorithm;
        import std.array;
        
        auto result = new IntOrStr[](T.length);
        foreach (i, val; vals)
        {
                result[i] = IntOrStr(val);
        }
        
        return result;
}

void main()
{
        IntOrStr[] arr = makeIntOrStrArray(4, "five");
}

Thanks.

On Sunday, 8 March 2015 at 18:57:38 UTC, Kagamin wrote:

http://dpaste.dzfl.pl/2c8d4a7d9ef0 like this.
struct IntString
{
        string svalue;
        this(string s){ svalue=s; }
        this(int i){ ivalue=i; }
        int ivalue() const
        {
                assert(svalue.length==0);
                return cast(int)svalue.ptr;
        }
        void ivalue(int i)
        {
                svalue=cast(string)(cast(char*)0)[i..i];
        }
}

int main()
{
        auto s=IntString(5);
        assert(s.ivalue==5);
        s.ivalue=-6;
        assert(s.ivalue==-6);
        return 0;
}

Thanks.