Re: question about ref keyword

[ag0aep6g via Digitalmars-d-learn]

On Thursday, 18 March 2021 at 16:59:24 UTC, Jack wrote:

let's assume this class:

class C
{
private S m_s;

this()
{
m_s = S(30);
}

ref S value() { return m_s; }
ref S value(ref S s)
{
return m_s = s;
}
}

and I do something like this:

auto s1 = S(40);
auto c = new C();
c.value = s1;
s1.n = 80;


give that value has ref in its signature, the s1 is passed as a 
"pointer" right?


right

also, when I do: m_s = s; m_s is a copy of s1 or a reference to 
it?


a copy

setting s1.n to 80 in the next line doesn't seem to change 
c.value so it seems it passed s1 as a pointer but when it comes 
to assignment a copy was made?


You got it.

If you want the pointer, you can get it taking the address of s: 
`S* p = `.

question about ref keyword

[Jack via Digitalmars-d-learn]

let's assume this class:

class C
{
private S m_s;

this()
{
m_s = S(30);
}

ref S value() { return m_s; }
ref S value(ref S s)
{
return m_s = s;
}
}

and I do something like this:

auto s1 = S(40);
auto c = new C();
c.value = s1;
s1.n = 80;


give that value has ref in its signature, the s1 is passed as a 
"pointer" right? also, when I do: m_s = s; m_s is a copy of s1 or 
a reference to it? setting s1.n to 80 in the next line doesn't 
seem to change c.value so it seems it passed s1 as a pointer but 
when it comes to assignment a copy was made?