fn main() {
// Declare a variable binding
let a_binding
{
let x = 2
// Initialize the binding
a_binding = x * x
}
println!("a binding: {}", a_binding)
let another_binding
// Error! Use of uninitialized binding
println!("another binding: {}", another_binding)
// FIXME ^ Comment out this line
another_binding = 1
println!("another binding: {}", another_binding)
}
编译器禁止使用未初始化变量，因为这将导致不确定的行为。