1
我正在使用特徵做矩陣加法。我被通用類型不匹配卡住了。我的代碼如下:在鏽跡中使用特徵的泛型類型不匹配
use std::{ops, fmt};
#[derive(PartialEq, Debug)]
pub struct Matrix<T> {
data: Vec<T>,
row: usize,
col: usize,
}
impl<T: Copy> Matrix<T> {
/// Creates a new matrix of `row` rows and `col` columns, and initializes
/// the matrix with the elements in `values` in row-major order.
pub fn new(row: usize, col: usize, values: &[T]) -> Matrix<T> {
Matrix {
data: values.to_vec(), // make copy and convert &[T] to vector type
row: row,
col: col,
}
}
}
impl<T: ops::Add<Output = T> + Copy> ops::Add for Matrix<T> {
type Output = Self;
/// Returns the sum of `self` and `rhs`. If `self.row != rhs.row || self.col != rhs.col`, panic.
fn add(self, rhs: Self) -> Self::Output {
assert!(self.col == rhs.col);
assert!(self.row == rhs.row);
let mut newdata = Vec::new(); // make a new vector to store result
let mut sum: i32; // temp variable to record each addition
for num1 in self.data.iter() {
for num2 in rhs.data.iter() {
sum = *num1 + *num2;
newdata.push(sum)
}
}
Matrix {
data: newdata, // finally, return addition result using new_data
row: self.row,
col: self.col,
}
}
}
fn main() {
let x = Matrix::new(2, 3, &[-6, -5, 0, 1, 2, 3]);
let y = Matrix::new(2, 3, &[0, 1, 0, 0, 0, 0]);
// z = x + y;
}
編譯程序,我得到了類型不匹配的兩個錯誤:
error[E0308]: mismatched types
--> src/main.rs:36:23
|
36 | sum = *num1 + *num2;
| ^^^^^^^^^^^^^ expected i32, found type parameter
|
= note: expected type `i32`
= note: found type `T`
error[E0308]: mismatched types
--> src/main.rs:41:9
|
41 | Matrix {
| ^expected type parameter, found i32
|
= note: expected type `Matrix<T>`
= note: found type `Matrix<i32>`
我的想法:
num1
將DEREF載體,並得到一個整數類型,這就是爲什麼我使用總和來記錄結果。- 我想在函數結尾返回一個
Matrix
類型的值。
怎麼回事?