Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Add "take a copy for immediate local use" case to F.16 #2172

Merged
merged 1 commit into from
Apr 11, 2024
Merged

Add "take a copy for immediate local use" case to F.16 #2172

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
3 changes: 2 additions & 1 deletion CppCoreGuidelines.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -3007,7 +3007,8 @@ When copying is cheap, nothing beats the simplicity and safety of copying, and f
For advanced uses (only), where you really need to optimize for rvalues passed to "input-only" parameters:

* If the function is going to unconditionally move from the argument, take it by `&&`. See [F.18](#Rf-consume).
* If the function is going to keep a copy of the argument, in addition to passing by `const&` (for lvalues),
* If the function is going to keep a locally modifiable copy of the argument only for its own local use, taking it by value is fine
* If the function is going to keep a copy of the argument to pass to another destination (to another function, or store in a non-local location), in addition to passing by `const&` (for lvalues),
add an overload that passes the parameter by `&&` (for rvalues) and in the body `std::move`s it to its destination. Essentially this overloads a "will-move-from"; see [F.18](#Rf-consume).
* In special cases, such as multiple "input + copy" parameters, consider using perfect forwarding. See [F.19](#Rf-forward).

Expand Down
Loading