77 lines
1.9 KiB
Zig
77 lines
1.9 KiB
Zig
//
|
|
// Struct types are always "anonymous" until we give them a name:
|
|
//
|
|
// struct {};
|
|
//
|
|
// So far, we've been giving struct types a name like so:
|
|
//
|
|
// const Foo = struct {};
|
|
//
|
|
// * The value of @typeName(Foo) is "Foo".
|
|
//
|
|
// A struct is also given a name when you return it from a
|
|
// function:
|
|
//
|
|
// fn Bar() type {
|
|
// return struct {};
|
|
// }
|
|
//
|
|
// const MyBar = Bar(); // store the struct type
|
|
// const bar = Bar() {}; // create instance of the struct
|
|
//
|
|
// * The value of @typeName(Bar()) is "Bar()".
|
|
// * The value of @typeName(MyBar) is "Bar()".
|
|
// * The value of @typeName(@TypeOf(bar)) is "Bar()".
|
|
//
|
|
// You can also have completely anonymous structs. The value
|
|
// of @typeName(struct {}) is "struct:<position in source>".
|
|
//
|
|
const print = @import("std").debug.print;
|
|
|
|
// This function creates a generic data structure by returning an
|
|
// anonymous struct type (which will no longer be anonymous AFTER
|
|
// it's returned from the function).
|
|
fn Circle(comptime T: type) type {
|
|
return struct {
|
|
center_x: T,
|
|
center_y: T,
|
|
radius: T,
|
|
};
|
|
}
|
|
|
|
pub fn main() void {
|
|
//
|
|
// See if you can complete these two variable initialization
|
|
// expressions to create instances of circle struct types
|
|
// which can hold these values:
|
|
//
|
|
// * circle1 should hold i32 integers
|
|
// * circle2 should hold f32 floats
|
|
//
|
|
var circle1 = Circle(i32){
|
|
.center_x = 25,
|
|
.center_y = 70,
|
|
.radius = 15,
|
|
};
|
|
|
|
var circle2 = Circle(f32){
|
|
.center_x = 25.234,
|
|
.center_y = 70.999,
|
|
.radius = 15.714,
|
|
};
|
|
|
|
print("[{s}: {},{},{}] ", .{
|
|
@typeName(@TypeOf(circle1)),
|
|
circle1.center_x,
|
|
circle1.center_y,
|
|
circle1.radius,
|
|
});
|
|
|
|
print("[{s}: {d:.1},{d:.1},{d:.1}]\n", .{
|
|
@typeName(@TypeOf(circle2)),
|
|
circle2.center_x,
|
|
circle2.center_y,
|
|
circle2.radius,
|
|
});
|
|
}
|