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Reworded "consume" to "will-move-from" parameters

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To improve clarity since the wording was causing confusion
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hsutter 2018-04-16 11:06:48 -07:00
parent 99b997b6f0
commit cea965f610
1 changed files with 5 additions and 5 deletions
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CppCoreGuidelines.md
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@ -2285,7 +2285,7 @@ Parameter passing expression rules:
* [F.15: Prefer simple and conventional ways of passing information](#Rf-conventional) * [F.15: Prefer simple and conventional ways of passing information](#Rf-conventional)
* [F.16: For "in" parameters, pass cheaply-copied types by value and others by reference to `const`](#Rf-in) * [F.16: For "in" parameters, pass cheaply-copied types by value and others by reference to `const`](#Rf-in)
* [F.17: For "in-out" parameters, pass by reference to non-`const`](#Rf-inout) * [F.17: For "in-out" parameters, pass by reference to non-`const`](#Rf-inout)
* [F.18: For "consume" parameters, pass by `X&&` and `std::move` the parameter](#Rf-consume) * [F.18: For "will-move-from" parameters, pass by `X&&` and `std::move` the parameter](#Rf-consume)
* [F.19: For "forward" parameters, pass by `TP&&` and only `std::forward` the parameter](#Rf-forward) * [F.19: For "forward" parameters, pass by `TP&&` and only `std::forward` the parameter](#Rf-forward)
* [F.20: For "out" output values, prefer return values to output parameters](#Rf-out) * [F.20: For "out" output values, prefer return values to output parameters](#Rf-out)
* [F.21: To return multiple "out" values, prefer returning a tuple or struct](#Rf-out-multi) * [F.21: To return multiple "out" values, prefer returning a tuple or struct](#Rf-out-multi)
@ -2835,7 +2835,7 @@ For advanced uses (only), where you really need to optimize for rvalues passed t
* 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 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 copy of the argument, 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 "consume"; see [F.18](#Rf-consume). 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). * In special cases, such as multiple "input + copy" parameters, consider using perfect forwarding. See [F.19](#Rf-forward).
##### Example ##### Example
@ -2845,7 +2845,7 @@ For advanced uses (only), where you really need to optimize for rvalues passed t
// suffix is input-only but not as cheap as an int, pass by const& // suffix is input-only but not as cheap as an int, pass by const&
string& concatenate(string&, const string& suffix); string& concatenate(string&, const string& suffix);
void sink(unique_ptr<widget>); // input only, and consumes the widget void sink(unique_ptr<widget>); // input only, and moves ownership of the widget
Avoid "esoteric techniques" such as: Avoid "esoteric techniques" such as:
@ -2918,7 +2918,7 @@ A bad logic error can happen if the writer of `g()` incorrectly assumes the size
* (Moderate) ((Foundation)) Warn about functions regarding reference to non-`const` parameters that do *not* write to them. * (Moderate) ((Foundation)) Warn about functions regarding reference to non-`const` parameters that do *not* write to them.
* (Simple) ((Foundation)) Warn when a non-`const` parameter being passed by reference is `move`d. * (Simple) ((Foundation)) Warn when a non-`const` parameter being passed by reference is `move`d.
### <a name="Rf-consume"></a>F.18: For "consume" parameters, pass by `X&&` and `std::move` the parameter ### <a name="Rf-consume"></a>F.18: For "will-move-from" parameters, pass by `X&&` and `std::move` the parameter
##### Reason ##### Reason
@ -9349,7 +9349,7 @@ Using `unique_ptr` in this way both documents and enforces the function call's o
##### Example ##### Example
void sink(unique_ptr<widget>); // consumes the widget void sink(unique_ptr<widget>); // takes ownership of the widget
void uses(widget*); // just uses the widget void uses(widget*); // just uses the widget