Mirrors/CppCoreGuidelines
1
0
Fork 0
mirror of https://github.com/isocpp/CppCoreGuidelines.git synced 2025-12-17 12:44:42 +03:00
Code Issues Actions Packages Projects Releases Wiki Activity

Revise cast guidance following upstream edits

Browse Source
This commit is contained in:
Zachary Henkel
2017-05-24 15:31:11 -05:00
parent 6a7552db21
commit 2cd9993ae4
1 changed files with 9 additions and 7 deletions
Download Patch File Download Diff File Expand all files Collapse all files

16
CppCoreGuidelines.md
View File

@@ -11602,7 +11602,8 @@ Surprised? I'm just glad I didn't crash the program.
##### Note ##### Note
Programmer who write casts typically assumes that they know what they are doing. Programmers who write casts typically assume that they know what they are doing,
or that writing a cast makes the program "easier to read".
In fact, they often disable the general rules for using values. In fact, they often disable the general rules for using values.
Overload resolution and template instantiation usually pick the right function if there is a right function to pick. Overload resolution and template instantiation usually pick the right function if there is a right function to pick.
If there is not, maybe there ought to be, rather than applying a local fix (cast). If there is not, maybe there ought to be, rather than applying a local fix (cast).
@@ -11623,16 +11624,14 @@ Casts are widely (mis) used. Modern C++ has constructs that eliminate the need f
* Use templates * Use templates
* Use `std::variant` * Use `std::variant`
* Rely on the well defined, safe, implicit conversions between pointer types
##### Enforcement ##### Enforcement
* Force the elimination of C-style casts * Force the elimination of C-style casts
* Warn against named casts
* Warn against unnecessary casts.
* Warn if there are many functional style casts (there is an obvious problem in quantifying 'many'). * Warn if there are many functional style casts (there is an obvious problem in quantifying 'many').
* The [type profile](#Pro-type-reinterpretcast) bans `reinterpret_cast`. * The [type profile](#Pro-type-reinterpretcast) bans `reinterpret_cast`.
* Warn against [unnecessary pointer casts](#Pro-type-unnecessarycast).
### <a name="Res-casts-named"></a>ES.49: If you must use a cast, use a named cast ### <a name="Res-casts-named"></a>ES.49: If you must use a cast, use a named cast
@@ -11694,6 +11693,7 @@ for example.)
* Flag C-style and functional casts. * Flag C-style and functional casts.
* The [type profile](#Pro-type-reinterpretcast) bans `reinterpret_cast`. * The [type profile](#Pro-type-reinterpretcast) bans `reinterpret_cast`.
* The [type profile](#Pro-type-arithmeticcast) warns when using `static_cast` between arithmetic types.
### <a name="Res-casts-const"></a>ES.50: Don't cast away `const` ### <a name="Res-casts-const"></a>ES.50: Don't cast away `const`
@@ -19399,8 +19399,10 @@ An implementation of this profile shall recognize the following patterns in sour
Type safety profile summary: Type safety profile summary:
* <a name="Pro-type-reinterpretcast"></a>Type.1: Don't use `reinterpret_cast`: * <a name="Pro-type-avoidcasts"></a>Type.1: [Avoid casts](#Res-casts):
A strict version of [Avoid casts](#Res-casts) and [prefer named casts](#Res-casts-named). * <a name="Pro-type-reinterpretcast"></a>Don't use `reinterpret_cast`; A strict version of [Avoid casts](#Res-casts) and [prefer named casts](#Res-casts-named).
* <a name="Pro-type-arithmeticcast"></a>Don't a `static_cast` for arithmetic types; A strict version of [Avoid casts](#Res-casts) and [prefer named casts](#Res-casts-named).
* <a name="Pro-type-unnecessarycast"></a>Don't use pointer unnecessary pointer casts; A strict version of [Avoid casts](#Res-casts)
* <a name="Pro-type-downcast"></a>Type.2: Don't use `static_cast` to downcast: * <a name="Pro-type-downcast"></a>Type.2: Don't use `static_cast` to downcast:
[Use `dynamic_cast` instead](#Rh-dynamic_cast). [Use `dynamic_cast` instead](#Rh-dynamic_cast).
* <a name="Pro-type-constcast"></a>Type.3: Don't use `const_cast` to cast away `const` (i.e., at all): * <a name="Pro-type-constcast"></a>Type.3: Don't use `const_cast` to cast away `const` (i.e., at all):