22b4470f2a
Update all links to C++ Core Guidelines to `e49158a`.
Refresh done using the following script and some manual edits:
db76e34e74/personal/fred-tingaud/rspec/refresh-cppcoreguidelines.py
When re-using this script, be mindful that:
- it does not cover `shared_content`
- it does not properly escape inline code in links (e.g., "[=]" or "`mutex`es")
- it does not change `C++` to `{cpp}` in link titles.
Co-authored-by: Marco Borgeaud <marco.borgeaud@sonarsource.com>
50 lines
1.6 KiB
Plaintext
50 lines
1.6 KiB
Plaintext
== Why is this an issue?
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When you call `empty()` or `is_empty()`, it clearly communicates the code's intention, which is to check if the collection is empty. Using `size() == 0` for this purpose is less direct and makes the code slightly more complex.
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Moreover, depending on the implementation, the `size()`, `length()`, or `count()` methods can have a time complexity of `O(n)` where `n` is the number of elements in the collection. On the other hand, `empty()` and `is_empty()` simply check if there is at least one element in the collection, which is a constant time operation, `O(1)`.
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[source,cpp,diff-id=1,diff-type=noncompliant]
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----
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void fun(const std::vector<int> &myVector) {
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if (myVector.size() == 0) { // Noncompliant
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// do something
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}
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}
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----
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Prefer using `empty()` or `is_empty()` to test for emptiness over `size()`, `length()`, or `count()`.
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[source,cpp,diff-id=1,diff-type=compliant]
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----
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void fun(const std::vector<int> &myVector) {
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if (myVector.empty()) {
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// do something
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}
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}
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----
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== Resources
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=== External coding guidelines
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* {cpp} Core Guidelines - https://github.com/isocpp/CppCoreGuidelines/blob/e49158a/CppCoreGuidelines.md#t143-dont-write-unintentionally-non-generic-code[T.143: Don't write unintentionally non-generic code]
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ifdef::env-github,rspecator-view[]
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'''
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== Implementation Specification
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(visible only on this page)
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=== Message
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Use empty() or is_empty() to check whether the container is empty or not.
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'''
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== Comments And Links
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(visible only on this page)
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include::../comments-and-links.adoc[]
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endif::env-github,rspecator-view[]
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