fix: typo

contents/basic/converse.md

@@ -43,7 +43,7 @@ fn main() {
 let mut values: [i32; 2] = [1, 2];
 let p1: *mut i32 = values.as_mut_ptr();
 let first_address = p1 as usize; // 将p1内存地址转换为一个整数
-let second_address = first_address + 4; // 4 == std:mem::size_of::<i32>()，i32类型占用4个字节，因此将内存地址 + 4
+let second_address = first_address + 4; // 4 == std::mem::size_of::<i32>()，i32类型占用4个字节，因此将内存地址 + 4
 let p2 = second_address as *mut i32; // 访问该地址指向的下一个整数p2
 unsafe {
     *p2 += 1;