This is now touched on in the second edition of The Rust Programming Language. However, let’s dive in a bit in addition. Let us start with a simpler example. When is it appropriate to use a trait method? There are multiple ways to provide late binding: trait MyTrait { fn hello_word(&self) -> String; } Or: … Read more
2mantissa bits + 1 + 1 The +1 in the exponent (mantissa bits + 1) is because, if the mantissa contains abcdef… the number it represents is actually 1.abcdef… × 2^e, providing an extra implicit bit of precision. Therefore, the first integer that cannot be accurately represented and will be rounded is: For float, 16,777,217 … Read more
The biggest/largest integer that can be stored in a double without losing precision is the same as the largest possible value of a double. That is, DBL_MAX or approximately 1.8 × 10308 (if your double is an IEEE 754 64-bit double). It’s an integer. It’s represented exactly. What more do you want? Go on, ask me what … Read more
You can use the std::any::type_name function. This doesn’t need a nightly compiler or an external crate, and the results are quite correct: fn print_type_of<T>(_: &T) { println!(“{}”, std::any::type_name::<T>()) } fn main() { let s = “Hello”; let i = 42; print_type_of(&s); // &str print_type_of(&i); // i32 print_type_of(&main); // playground::main print_type_of(&print_type_of::<i32>); // playground::print_type_of<i32> print_type_of(&{ || “Hi!” … Read more