StarMirror/CppCoreGuidelines
1
0
Fork 0
mirror of https://github.com/isocpp/CppCoreGuidelines.git synced 2024-03-22 13:30:58 +08:00
Code Issues Projects Releases Wiki Activity

Merge pull request #520 from PiotrSliwa/F.53

Browse Source 
More comprehensive example and enforcements for F.53
This commit is contained in:
Andrew Pardoe 2016-03-20 09:20:48 -07:00
commit 3fe4e40ae9
1 changed files with 16 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

21
CppCoreGuidelines.md
View File

@ -3163,18 +3163,29 @@ This is a simple three-stage parallel pipeline. Each `stage` object encapsulates
Pointers and references to locals shouldn't outlive their scope. Lambdas that capture by reference are just another place to store a reference to a local object, and shouldn't do so if they (or a copy) outlive the scope. Pointers and references to locals shouldn't outlive their scope. Lambdas that capture by reference are just another place to store a reference to a local object, and shouldn't do so if they (or a copy) outlive the scope.
##### Example ##### Example, bad
{ {
// ... int local = 42;
thread_pool.queue_work([&]{ process(local); }); // Want a reference to local.
// Note, that after program exits this scope,
// local no longer exists, therefore
// process() call will have undefined behavior!
}
// a, b, c are local variables ##### Example, good
background_thread.queue_work([=]{ process(a, b, c); }); // want copies of a, b, and c
{
int local = 42;
thread_pool.queue_work([=]{ process(local); }); // Want a copy of local.
// Since a copy of local is made, it will be
// available at all times for the call.
} }
##### Enforcement ##### Enforcement
??? * (Simple) Warn when capture-list contains a reference to a locally declared variable
* (Complex) Flag when capture-list contains a reference to a locally declared variable and the lambda is passed to a non-`const` and non-local context
### <a name="Rf-this-capture"></a>F.54: If you capture `this`, capture all variables explicitly (no default capture) ### <a name="Rf-this-capture"></a>F.54: If you capture `this`, capture all variables explicitly (no default capture)