module test;

​

import std : writeln, writefln, assumeUnique;

import std.conv : to;

​

void main()

{

    string str = "abc;def;ab".dup; // allocates the string in the heap

    char* w = cast(char*)str;

    writeln(replaceChar(w, str.length, ';', 'X'));

}

​

immutable(char)[] replaceChar(char* str, ulong len, char ch1, char ch2)

{

    for (ulong i = 0; i < len; i++)

    {

        if (str[i] == ch1)

        {

            writefln("Found %c at str[%d]", ch1, i); // fine

​

            // problem is with this next line:

            // the line works fine using DMD on windows - but crashes if using LDC on windows

            // On Linux, both DMD and LDC -> sigsegv

            str[i] = ch2;

            // seems simple enough

            // - just replace the char currently in element str[i]) with 'X'

        }

    }

    return assumeUnique(str[0..len]); // you can use str[0..len].idup but it allocates although is safe

}