64 lines
1.0 KiB
D
64 lines
1.0 KiB
D
import std.stdio: writeln;
|
|
|
|
// classes are a reference type, structs are a value type
|
|
class Hello {
|
|
string name;
|
|
|
|
this(string s) {
|
|
name = s;
|
|
}
|
|
|
|
void print() {
|
|
writeln("hello, ", name, "!");
|
|
}
|
|
|
|
// a func for copying an object
|
|
Hello dup() {
|
|
return new Hello(name);
|
|
}
|
|
}
|
|
|
|
void main() {
|
|
// class initialization
|
|
Hello hello = new Hello("John"); // use -vgc flag to display GC allocations
|
|
|
|
// allocating on the stack using "scope" keyword
|
|
//scope Hello hello = new Hello("John");
|
|
|
|
if(hello is null) {
|
|
writeln("Error! Could not initialize hello!");
|
|
return;
|
|
}
|
|
|
|
/* scope(...) { ... } expressions:
|
|
scope(success) { ... } => is executed if the scope exits successfully
|
|
scope(failure) { ... } => is executed if the scope exits due to an exception
|
|
scope(exit) { ... } => is executed regardless of the previous two cases
|
|
*/
|
|
|
|
scope(exit) {
|
|
writeln("goodbuy...");
|
|
}
|
|
|
|
hello.print();
|
|
|
|
// making a reference
|
|
Hello ref_hello = hello;
|
|
|
|
// making a copy
|
|
Hello copy_hello = hello.dup();
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|