72 lines
2 KiB
Rust
72 lines
2 KiB
Rust
// Copyright 2014-2018 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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use std::iter::repeat;
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fn main() {
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resize_vector();
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extend_vector();
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mixed_extend_resize_vector();
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}
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fn extend_vector() {
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// Extend with constant expression
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let len = 300;
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let mut vec1 = Vec::with_capacity(len);
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vec1.extend(repeat(0).take(len));
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// Extend with len expression
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let mut vec2 = Vec::with_capacity(len - 10);
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vec2.extend(repeat(0).take(len - 10));
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// Extend with mismatching expression should not be warned
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let mut vec3 = Vec::with_capacity(24322);
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vec3.extend(repeat(0).take(2));
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}
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fn mixed_extend_resize_vector() {
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// Mismatching len
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let mut mismatching_len = Vec::with_capacity(30);
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mismatching_len.extend(repeat(0).take(40));
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// Slow initialization
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let mut resized_vec = Vec::with_capacity(30);
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resized_vec.resize(30, 0);
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let mut extend_vec = Vec::with_capacity(30);
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extend_vec.extend(repeat(0).take(30));
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}
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fn resize_vector() {
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// Resize with constant expression
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let len = 300;
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let mut vec1 = Vec::with_capacity(len);
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vec1.resize(len, 0);
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// Resize mismatch len
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let mut vec2 = Vec::with_capacity(200);
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vec2.resize(10, 0);
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// Resize with len expression
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let mut vec3 = Vec::with_capacity(len - 10);
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vec3.resize(len - 10, 0);
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// Reinitialization should be warned
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vec1 = Vec::with_capacity(10);
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vec1.resize(10, 0);
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}
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fn do_stuff(vec: &mut Vec<u8>) {}
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fn extend_vector_with_manipulations_between() {
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let len = 300;
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let mut vec1: Vec<u8> = Vec::with_capacity(len);
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do_stuff(&mut vec1);
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vec1.extend(repeat(0).take(len));
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}
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