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Merge pull request #426 from ascherer/fix-const-ness

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Fix `const`-ness consistency.
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hsutter 2015-12-11 08:16:14 -08:00
commit e28faccbf3
1 changed files with 2 additions and 2 deletions
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@ -2342,7 +2342,7 @@ Unique owner types that are move-only and cheap-to-move, such as `unique_ptr`, c
If the object is to be passed onward to other code and not directly used by this function, we want to make this function agnostic to the argument `const`-ness and rvalue-ness. If the object is to be passed onward to other code and not directly used by this function, we want to make this function agnostic to the argument `const`-ness and rvalue-ness.
In that case, and only that case, make the parameter `TP&&` where `TP` is a template type parameter -- it both *ignores* and *preserves* `const`-ness and rvalue-ness. Therefore any code that uses a `T&&` is implicitly declaring that it itself doesn't care about the variable's `const`'-ness and rvalue-ness (because it is ignored), but that intends to pass the value onward to other code that does care about `const`-ness and rvalue-ness (because it is preserved). When used as a parameter `TP&&` is safe because any temporary objects passed from the caller will live for the duration of the function call. A parameter of type `TP&&` should essentially always be passed onward via `std::forward` in the body of the function. In that case, and only that case, make the parameter `TP&&` where `TP` is a template type parameter -- it both *ignores* and *preserves* `const`-ness and rvalue-ness. Therefore any code that uses a `T&&` is implicitly declaring that it itself doesn't care about the variable's `const`-ness and rvalue-ness (because it is ignored), but that intends to pass the value onward to other code that does care about `const`-ness and rvalue-ness (because it is preserved). When used as a parameter `TP&&` is safe because any temporary objects passed from the caller will live for the duration of the function call. A parameter of type `TP&&` should essentially always be passed onward via `std::forward` in the body of the function.
##### Example ##### Example
@ -14144,7 +14144,7 @@ Alternatively, we will decide that no change is needed and delete the entry.
* Const member functions should be thread safe "¦ aka, but I don't really change the variable, just assign it a value the first time its called "¦ argh * Const member functions should be thread safe "¦ aka, but I don't really change the variable, just assign it a value the first time its called "¦ argh
* Always initialize variables, use initialization lists for member variables. * Always initialize variables, use initialization lists for member variables.
* Anyone writing a public interface which takes or returns void* should have their toes set on fire. That one has been a personal favorite of mine for a number of years. :) * Anyone writing a public interface which takes or returns void* should have their toes set on fire. That one has been a personal favorite of mine for a number of years. :)
* Use `const`'ness wherever possible: member functions, variables and (yippee) `const_iterators` * Use `const`-ness wherever possible: member functions, variables and (yippee) `const_iterators`
* Use `auto` * Use `auto`
* `(size)` vs. `{initializers}` vs. `{Extent{size}}` * `(size)` vs. `{initializers}` vs. `{Extent{size}}`
* Don't overabstract * Don't overabstract