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struct MyPair:
var first: Int
var second: Int
fn __init__(inout self, first: Int, second: Int):
self.first = first
self.second = second
fn __lt__(self, rhs: MyPair) -> Bool:
return self.first < rhs.first or
(self.first == rhs.first and
self.second < rhs.second)
fn dump(self):
print(self.first, self.second)
fn main():
let mine = MyPair(2, 4)
mine.dump() # 2 4
@value
struct DefaultParams[msg: StringLiteral = "woof"]:
alias message = msg
fn main():
print(DefaultParams[]().message) # woof
print(DefaultParams["meow"]().message) # meow
@value
struct Thing[param: Int]: pass
fn foo[value: Int]():
print(value)
fn main():
print(Thing[2].param) # 2
let x = Thing[9]()
print(x.param) # 9
let y = Thing[12]()
alias constant = y.param + 4
foo[constant]() # 16
struct KwParamStruct[a: Int, msg: String = "🔥mojo🔥"]:
fn __init__(inout self):
print(msg, a)
fn main():
KwParamStruct[a=42]() # 🔥mojo🔥 42
KwParamStruct[5, msg="hello"]() # hello 5
KwParamStruct[msg="hello", a=42]() # hello 42
@value
struct Thing[v: Int]: pass
struct CtadStructWithDefault[a: Int, b: Int, c: Int = 8]:
fn __init__(inout self, x: Thing[a]):
print("hello", a, b, c)
@staticmethod
fn foo(x: Thing[a]):
print("🔥", a, b, c)
fn main():
_ = CtadStructWithDefault[b=7](Thing[6]()) # hello 6 7 8
CtadStructWithDefault[b=7].foo(Thing[6]()) # 🔥 6 7 8
__getitem__@value
struct MyStruct:
fn __getitem__(self, x: Int, y: Int, z: Int) -> Int:
return x * y + z
fn main():
print(MyStruct()[z=7, x=3, y=5]) # 22
struct Complex:
var re: Float32
var im: Float32
fn __init__(inout self, x: Float32):
"""Постройте комплексное число по действительному числу."""
self.re = x
self.im = 0.0
fn __init__(inout self, r: Float32, i: Float32):
"""Постройте комплексное число, зная его действительную и мнимую составляющие."""
self.re = r
self.im = i
__copyinit__ и __moveinit__from memory.unsafe import Pointer
struct HeapArray:
var data: Pointer[Int]
var size: Int
var cap: Int
fn __init__(inout self):
self.cap = 16
self.size = 0
self.data = Pointer[Int].alloc(self.cap)
fn __init__(inout self, size: Int, val: Int):
self.cap = size * 2
self.size = size
self.data = Pointer[Int].alloc(self.cap)
for i in range(self.size):
self.data.store(i, val)
fn __del__(owned self):
self.data.free()
fn dump(self):
print_no_newline("[")
for i in range(self.size):
if i > 0:
print_no_newline(", ")
print_no_newline(self.data.load(i))
print("]")
fn main():
let a = HeapArray(3, 1)
a.dump() # [1, 1, 1]
# Если бы не __copyinit__, то 'ERROR: Vector doesn't implement __copyinit__':
let b = a
b.dump() # [1, 1, 1]
a.dump() # [1, 1, 1]
struct UniquePointer:
var ptr: Int
fn __init__(inout self, ptr: Int):
self.ptr = ptr
fn __moveinit__(inout self, owned existing: Self):
self.ptr = existing.ptr
fn __del__(owned self):
self.ptr = 0
fn take_ptr(owned p: UniquePointer):
print("take_ptr")
print(p.ptr)
fn use_ptr(borrowed p: UniquePointer):
print("use_ptr")
print(p.ptr)
fn main():
let p = UniquePointer(100)
use_ptr(p) # Переход к функции заимствования.
take_ptr(p^) # Передаёт право собственности на значение `p` другой функции.
# Uncomment to see an error:
# use_ptr(p) # ERROR: `p` здесь больше недействителен!
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