- Qt Creator Manual
- C++ Quick Fixes
- Qt Creator Manual 13.0.0

Reference

# C++ Quick Fixes

If you use the Clang code model to parse the C++ files, you get Clang fix-it hints in the Edit mode. Use the standard ways of activating quick fixes, or select the fixes that are applicable on a line in the context menu in the left margin of the code editor.

Apply the following types of quick fixes to C++ code:

- Change binary operands
- Simplify if and while conditions (for example, move declarations out of if conditions)
- Modify strings (for example, set the encoding for a string to Latin-1, mark strings translatable, and convert symbol names to camel case)
- Create variable declarations
- Create function declarations and definitions

The following table summarizes the quick fixes for C++ code. The fix is available when the cursor is in the position described in the Activation column.

Quick Fix | Description | Activation
--- | --- | ---

Add Curly Braces

Adds curly braces to an if statement that does not have a compound statement. For example, rewrites

     if (a)
         b;

as

     if (a) {
         b;
     }

`if`

Move Declaration out of Condition

Moves a declaration out of an if or while condition to simplify the condition. For example, rewrites

     if (Type name = foo()) {}

as

     Type name = foo;
     if (name) {}

Name of the introduced variable

Rewrite Condition Using ||

Rewrites the expression according to De Morgan's laws. For example, rewrites:

     !a && !b

as

     !(a || b)

`&&`

Rewrite Using operator

Rewrites an expression negating it and using the inverse operator. For example, rewrites:

-      a op b

  as

       !(a invop b)

-      (a op b)

  as

       !(a invop b)

-      !(a op b)

  as

       (a invob b)

`<=`, `<`, `>`, `>=`, `==` or `!=`

Split Declaration

Splits a simple declaration into several declarations. For example, rewrites:

     int *a, b;

as

     int *a;
     int b;

Type name or variable name

Split if Statement

Splits an if statement into several statements. For example, rewrites:

     if (something && something_else) {
     }

as

     if (something) {
        if (something_else) {
        }
     }

and

     if (something || something_else)
         x;

with

     if (something)
         x;
     else if (something_else)
         x;

`&&` or `||`

Swap Operands

Rewrites an expression in the inverse order using the inverse operator. For example, rewrites:

     a op b

as

     b flipop a

`<=`, `<`, `>`, `>=`, `==`, `!=`, `&&` or `||`

Convert to Decimal | Converts an integer literal to decimal representation | Numeric literal
Convert to Hexadecimal | Converts an integer literal to hexadecimal representation | Numeric literal
Convert to Octal | Converts an integer literal to octal representation | Numeric literal

Convert to Objective-C String Literal

Converts a string literal to an Objective-C string literal if the file type is Objective-C(++). For example, rewrites the following strings

     "abcd"
     QLatin1String("abcd")
     QLatin1Literal("abcd")

as

     @"abcd"

String literal

Enclose in QLatin1Char()

Sets the encoding for a character to Latin-1, unless the character is already enclosed in QLatin1Char, QT_TRANSLATE_NOOP, tr, trUtf8, QLatin1Literal, or QLatin1String. For example, rewrites

     'a'

as

     QLatin1Char('a')

String literal

Enclose in QLatin1String()

Sets the encoding for a string to Latin-1, unless the string is already enclosed in QLatin1Char, QT_TRANSLATE_NOOP, tr, trUtf8, QLatin1Literal, or QLatin1String. For example, rewrites

     "abcd"

as

     QLatin1String("abcd")

String literal

Enclose in QByteArrayLiteral()

Converts a string to a byte array. For example, rewrites

     "abcd"

as

     QByteArrayLiteral("abcd")

String literal

Mark as Translatable

Marks a string translatable. For example, rewrites `"abcd"` with one of the following options, depending on which of them is available:

     tr("abcd")
     QCoreApplication::translate("CONTEXT", "abcd")
     QT_TRANSLATE_NOOP("GLOBAL", "abcd")

String literal

Add Definition in ...

Inserts a definition stub for a function declaration either in the header file (inside or outside the class) or in the implementation file. For free functions, inserts the definition after the declaration of the function or in the implementation file. Qualified names are minimized when possible, instead of always being fully expanded.

For example, rewrites

     Class Foo {
         void bar();
     };

as (inside class)

     Class Foo {
         void bar() {

         }
     };

as (outside class)

     Class Foo {
         void bar();
     };

     void Foo::bar()
     {

     }

as (in implementation file)

     // Header file
     Class Foo {
         void bar();
     };

     // Implementation file
     void Foo::bar()
     {

     }

Function name

Add `Function` Declaration | Inserts the member function declaration that matches the member function definition into the class declaration. The function can be `public`, `protected`, `private`, `public slot`, `protected slot`, or `private slot`. | Function name
Add Class Member | Adds a member declaration for the class member being initialized if it is not yet declared. If Qt Creator cannot automatically detect the data type of the member, you must add it. | Identifier
Create Implementations for Member Functions | Creates implementations for all member functions in one go. In the Member Function Implementations dialog, specify whether the member functions are generated inline or outside the class. | Function name
Switch with Next/Previous Parameter | Moves a parameter down or up one position in a parameter list. | Parameter in the declaration or definition of a function
Extract Function | Moves the selected code to a new function and replaces the block of code with a call to the new function. Enter a name for the function in the Extract Function Refactoring dialog. | Block of code selected
Extract Constant as Function Parameter | Replaces the selected literal and all its occurrences with the function parameter `newParameter`. The parameter `newParameter` will have the original literal as the default value. | Block of code selected

Add Local Declaration

Adds the type of an assignee, if the type of the right-hand side of the assignment is known. For example, rewrites

     a = foo();

as

     Type a = foo();

where Type is the return type of `foo()`

Assignee

Convert to Camel Case | Converts a symbol name to camel case, where elements of the name are joined without delimiter characters and the initial character of each element is capitalized. For example, rewrites `an_example_symbol` as `anExampleSymbol` and `AN_EXAMPLE_SYMBOL` as `AnExampleSymbol` | Identifier
Complete Switch Statement | Adds all possible cases to a switch statement of the type `enum` | `switch`

Generate Missing Q_PROPERTY Members

Adds missing members to a `Q_PROPERTY`:

- `read` function
- `write` function, if there is a WRITE
- `onChanged` signal, if there is a NOTIFY
- data member with the name `m_<propertyName>`

`Q_PROPERTY`

Generate Q_PROPERTY and Missing Members | Generates a Q_PROPERTY and adds missing members to it, as described above. | Class member
Generate Constant Q_PROPERTY and Missing Members | Generates a constant Q_PROPERTY and adds missing members to it, as described above. | Class member
Generate Q_PROPERTY and Missing Members with Reset Function | Generates a Q_PROPERTY and adds missing members to it, as described above, but with an additional `reset` function. | Class member
Apply Changes | Keeps function declarations and definitions synchronized by checking for the matching declaration or definition when you edit a function signature and by applying the changes to the matching code. | Function signature. When this fix is available, a light bulb icon appears:
Add #include for undeclared or forward declared identifier | Adds an `#include` directive to the current file to make the definition of a symbol available. | Undeclared identifier
Add Forward Declaration | Adds a forward declaration for an undeclared identifier operation. | Undeclared identifier

Reformat Pointers or References

Reformats declarations with pointers or references according to the code style settings for the current project. In case no project is open, the current global code style settings are used.

For example, rewrites:

     char*s;

as

     char *s;

When applied to selections, all suitable declarations in the selection are rewritten.

Declarations with pointers or references and selections that have such declarations

Create Getter and Setter Member Functions | Creates either both getter and setter member functions for member variables or only a getter or setter. | Member variable in class definition
Generate Getter and Setter | Creates getter and setter member functions for a member variable. | Member variable in class definition
Generate Getter | Creates a getter member function for a member variable. | Member variable in class definition
Generate Setter | Creates a setter member function for a member variable. | Member variable in class definition
Generate Constructor | Creates a constructor for a class. | Class definition

Move Function Definition

Moves a function definition to the implementation file, outside the class or back to its declaration. For example, rewrites:

     class Foo
     {
       void bar()
       {
           // do stuff here
       }
     };

as

     class Foo
     {
       void bar();
     };

     void Foo::bar() {
         // do stuff here
     }

Function signature

Move All Function Definitions

Moves all function definitions to the implementation file or outside the class. For example, rewrites:

     class Foo
     {
       void bar()
       {
           // do stuff here
       }
       void baz()
       {
           // do stuff here
       }
     };

as

     class Foo
     {
       void bar();
       void baz();
     };

     void Foo::bar() {
         // do stuff here
     }

     void Foo::baz() {
         // do stuff here
     }

Class name

Move Definition Here | Moves an existing function definition to its declaration. | Function declaration

Assign to Local Variable

Adds a local variable which stores the return value of a function call or a new expression. For example, rewrites:

     QString s;
     s.toLatin1();

as

     QString s;
     QByteArray latin1 = s.toLatin1();

and

     new Foo;

as

     Foo * localFoo = new Foo;

By default, Qt Creator uses the `auto` variable type when creating the variable. To label the variable with its actual type, select Preferences > C++ > Quick Fixes, and then deselect the Use type "auto" when creating new variables check box.

Function call or class name

Insert Virtual Functions of Base Classes | Inserts declarations and the corresponding definitions inside or outside the class or in an implementation file (if it exists). For more information, see Insert virtual functions. | Class or base class name

Optimize for-Loop

Rewrites post increment operators as pre increment operators and post decrement operators as pre decrement operators. It also moves other than string or numeric literals and id expressions from the condition of a for loop to its initializer. For example, rewrites:

     for (int i = 0; i < 3 * 2; i++)

as

     for (int i = 0, total = 3 * 2; i < total; ++i)

`for`

Escape String Literal as UTF-8 | Escapes non-ASCII characters in a string literal to hexadecimal escape sequences. String Literals are handled as UTF-8. | String literal
Unescape String Literal as UTF-8 | Unescapes octal or hexadecimal escape sequences in a string literal. String Literals are handled as UTF-8. | String literal

Convert to Stack Variable

Converts the selected pointer to a stack variable. For example, rewrites:

     QByteArray *foo = new QByteArray("foo");
     foo->append("bar");

as

     QByteArray foo("foo");
     foo.append("bar");

This operation is limited to work only within function scope. Also, the coding style for pointers and references is not respected yet.

Pointer Variable

Convert to Pointer

Converts the selected stack variable to a pointer. For example, rewrites:

     QByteArray foo = "foo";
     foo.append("bar");

as

     QByteArray *foo = new QByteArray("foo");
     foo->append("bar");

This operation is limited to work only within function scope. Also, the coding style for pointers and references is not respected yet.

Stack Variable

Remove `using namespace` and Adjust Type Names Accordingly | Remove occurrences of `using namespace` in the local scope and adjust type names accordingly. | `using` directive
Remove All Occurrences of `using namespace` in Global Scope and Adjust Type Names Accordingly | Remove all occurrences of `using namespace` in the global scope and adjust type names accordingly. | `using` directive
Convert connect() to Qt 5 Style | Converts a Qt 4 QObject::connect() to Qt 5 style. | QObject::connect() (Qt 4 style)
Convert Comment to C/C++ Style | Converts C-style comments into C++-style comments, and vice versa. Tries to preserve pretty layout and takes Doxygen and qdoc formatting into consideration, but you might need to clean up the results. | Code comment
Move Function Documentation to Declaration/Definition | Moves the documentation comment for a function between its declaration and definition. | Documentation comment for a function

See also Apply quick fixes, Find symbols, Rename symbols, Specify settings for quick fixes, QML Quick Fixes, and Quick Fixes.