On Thursday, 29 September 2016 at 07:10:44 UTC, Straivers wrote:
Hi,
Say I wanted to create an object that has a string member, and
I want the string to be allocated with the object contiguously
instead of as a pointer to another location (as a constructor
would do). For example:
class C {
this(int i, string s) {
this.i = i;
this.s = s.toUTF16z();
}
int i;
wstring s;
}
I want to allocate memory such that it looks like this:
[32-bit int][s.length * wchar.sizeof bytes]
I've considered using a separate function to create the class,
but I don't know how setting the length of the string would
behave. The only solution I can think of would be to have a
constructor like this:
this(int i, string s, void[] mem) {
emplace!int(mem.ptr, i);
auto t = cast(dchar[]) mem[int.sizeof .. $];
this.s.fill(s.byDChar())
}
Is there a better way to do this?
struct Foo
{
uint length;
wchar[0] str; //this is the equivalent of wchar_t[] in C. i.e
variable length.
}
auto newFoo(wstring s)
{
auto fooMem = new ubyte[ unit.sizeof +
wchar.sizeof*s.length];// you may need trailing '\0' if you are
trying to interoperate with C.
auto ret = cast(Foo*) fooMem;
ret.length = s.length;
memcpy(&ret.str,s.ptr, wchar.sizeof*s.length);
return ret;
}
