On Tuesday, 27 January 2015 at 09:01:39 UTC, ref2401 wrote:
For several times I've met struct(or static struct) usage in
Phobos for singleton pattern implementation. Unfortunately now
i can remember only core.runtime.Runtime.
So I've got a question. Why do Phobos guys use struct or static
struct for or singleton pattern implementation? Why don't use
static final class for this purpose?
You probably saw static member function.
Please take the following with a big grain of salt as I took it
out of my head:
We can divide the D static keyword usage into 3 types:
1. static variable
struct A{int a} // no static before declaration
static A s; //note that static is used for struct variable
storage class (lifetime)
static int b;
etc.
2. static declaration
static struct A{int a}; //static used for context unnesting
static int fun(){}; // static used also for removing scope context
etc.
3. static if
static if(compile_time_cond)
{
//this section of code will be taken into the binary, used for
meta programming
}
I don't think there is much (if any) use of static (type 1) for
singleton.
Piotrek
