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Diffstat (limited to 'src/tools/clippy/src/docs/slow_vector_initialization.txt')
-rw-r--r-- | src/tools/clippy/src/docs/slow_vector_initialization.txt | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/src/tools/clippy/src/docs/slow_vector_initialization.txt b/src/tools/clippy/src/docs/slow_vector_initialization.txt new file mode 100644 index 000000000..53442e179 --- /dev/null +++ b/src/tools/clippy/src/docs/slow_vector_initialization.txt @@ -0,0 +1,24 @@ +### What it does +Checks slow zero-filled vector initialization + +### Why is this bad? +These structures are non-idiomatic and less efficient than simply using +`vec![0; len]`. + +### Example +``` +let mut vec1 = Vec::with_capacity(len); +vec1.resize(len, 0); + +let mut vec1 = Vec::with_capacity(len); +vec1.resize(vec1.capacity(), 0); + +let mut vec2 = Vec::with_capacity(len); +vec2.extend(repeat(0).take(len)); +``` + +Use instead: +``` +let mut vec1 = vec![0; len]; +let mut vec2 = vec![0; len]; +```
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