Difference between revisions of "Krita/C++11"

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(Add list of features for consideration)
(List some features which will probably not be used)
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= General links to C++11 and Qt =
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= General links to about using C++11 =
'''Note:''' as would be expected from those interested in hot new technology, the writers of most of these links demonstrate Silicon Valley levels of extreme optimism.  Take this with a grain of salt.  There is no such thing as a free lunch.
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There have been a few links discussing mixing C++11 with Qt, and starting with Qt 5.6 C++11 support will be default. '''Note:''' as would be expected from those interested in hot new technology, the writers of most of these links demonstrate Silicon Valley levels of extreme optimism.  Take this with a grain of salt: there is no such thing as a free lunch.
  
 
* [http://www.ics.com/blog/qt-and-c11  ICS.com]
 
* [http://www.ics.com/blog/qt-and-c11  ICS.com]
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= Particular Features =
 
= Particular Features =
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Under "drawbacks," every item should list: "Programmers will face another feature they must learn about."
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=== Type Inference (auto) ===
 
=== Type Inference (auto) ===
 
'''Motivation:'''
 
'''Motivation:'''
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'''Recommendation:'''
 
'''Recommendation:'''
=== Universal and General Initialization ===
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=== General Initializer Lists ===
 
'''Motivation:'''
 
'''Motivation:'''
 
Member Initializers
 
Member Initializers
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'''Recommendation:'''
 
'''Recommendation:'''
=== Lambda ===
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=== Lambdas ===
 
'''Motivation:'''
 
'''Motivation:'''
 
Lambda expressions for slots
 
Lambda expressions for slots
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'''Recommendation:'''
 
'''Recommendation:'''
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=== enum class ===
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'''Motivation:'''
 +
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'''Drawbacks:'''
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 +
'''Recommendation:'''
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=== nullptr ===
 
=== nullptr ===
 
'''Motivation:'''
 
'''Motivation:'''
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'''Motivation:'''
 
'''Motivation:'''
  
'''Drawbacks:''' unique_ptr is unable to be copied, and therefore cannot be used inside Qt classes.  For example QVector<std::unique_ptr> is invalid, because QVector requires its members can be copied. This makes converting to unique_ptr arduous.
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'''Drawbacks:''' unique_ptr is unable to be copied, and therefore cannot be used inside Qt classes.  For example QVector<std::unique_ptr> is invalid, because QVector requires its members can be copied. This makes converting to unique_ptr a bit slow, since QVector<T *>  will have to be converted to std_array<unique_ptr<T*>>, and the owner will no.
  
 
'''Recommendation:'''
 
'''Recommendation:'''
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'''Recommendation:'''
 
'''Recommendation:'''
  
== Other C++11 features, less immediately useful ==  
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== C++11 features mostly for template programming ==  
* Extended Unions (already have QVariant)
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Krita makes very light use of templates.  These features are useful, coming across them in the code base will add complexity for new learners, and have not been necessary so far.
* New literal types (already have QString)
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* decltype
* Threads (Qt/KDE provide threading support already)
 
* shared_ptr (unique_ptr Qt already provides a
 
* Local types (mostly for advanced template programming)
 
 
* static_assert
 
* static_assert
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* std::function and std::bind
 
* variadic templates
 
* variadic templates
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 +
== Other C++11 features that probably cannot be used ==
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* Threads (Qt/KDE use an incompatible threading model)
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* shared_ptr and weak_ptr (Relies on C++ threading model; use KisSharedPointer)
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* New literal types (already have QString)
 +
* Extended Unions (already have QVariant)

Revision as of 01:52, 15 October 2015

General links to about using C++11

There have been a few links discussing mixing C++11 with Qt, and starting with Qt 5.6 C++11 support will be default. Note: as would be expected from those interested in hot new technology, the writers of most of these links demonstrate Silicon Valley levels of extreme optimism. Take this with a grain of salt: there is no such thing as a free lunch.

Particular Features

Under "drawbacks," every item should list: "Programmers will face another feature they must learn about."

Type Inference (auto)

Motivation:

Drawbacks:

Recommendation:

Range-based for loop

Motivation:

Drawbacks:

Recommendation:

General Initializer Lists

Motivation: Member Initializers Mixed uniform initialization

Drawbacks:

Recommendation:

Lambdas

Motivation: Lambda expressions for slots

Drawbacks:

Recommendation:

constexpr

Motivation:

Drawbacks:

Recommendation:

Override and final

Motivation:

Drawbacks:

Recommendation:

<algorithm>

Motivation:

Drawbacks:

Recommendation:

enum class

Motivation:

Drawbacks:

Recommendation:

nullptr

Motivation:

Drawbacks:

Recommendation:

Deleted and default class members

Motivation:

Drawbacks:

Recommendation:

unique_ptr

Motivation:

Drawbacks: unique_ptr is unable to be copied, and therefore cannot be used inside Qt classes. For example QVector<std::unique_ptr> is invalid, because QVector requires its members can be copied. This makes converting to unique_ptr a bit slow, since QVector<T *> will have to be converted to std_array<unique_ptr<T*>>, and the owner will no.

Recommendation:

Performance-related (rvalues)

http://thbecker.net/articles/rvalue_references/section_01.html

Move Constructors

Motivation:

Drawbacks:

Recommendation:

Reference Qualifiers

Motivation:

Drawbacks:

Recommendation:

C++11 features mostly for template programming

Krita makes very light use of templates. These features are useful, coming across them in the code base will add complexity for new learners, and have not been necessary so far.

  • decltype
  • static_assert
  • std::function and std::bind
  • variadic templates

Other C++11 features that probably cannot be used

  • Threads (Qt/KDE use an incompatible threading model)
  • shared_ptr and weak_ptr (Relies on C++ threading model; use KisSharedPointer)
  • New literal types (already have QString)
  • Extended Unions (already have QVariant)

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