-qkeyword

Category

Language element control

Pragma equivalent

None

Purpose

Controls whether the specified name is treated as a keyword or as an identifier whenever it appears in your program source.

Defaults

By default, all the built-in keywords defined in the C and C++ language standards are reserved as keywords.

Usage

You cannot add keywords to the language with this option. However, you can use -qnokeyword=keyword_name to disable built-in keywords, and use -qkeyword=keyword_name to reinstate those keywords.

This option can be used with all C++ built-in keywords.

This option can be used with the following keywords introduced by the C++11 standard:

Table 1. Keywords introduced by the C++11 standard

Keyword	Feature	-qlanglvl suboption
constexpr	Generalized constant expressions (C++11)	-qlanglvl=[no]constexpr
decltype	The decltype(expression) type specifier (C++11)	-qlanglvl=[no]decltype
nullptr	nullptr (C++11)	-qlanglvl=[no]nullptr
static_assert	static_assert declaration (C++11)	-qlanglvl=[no]static_assert

These keywords are reserved at all C++ language levels by default. The -qlanglvl suboption of each feature or the -qlanglvl=[no]extended0x group option can only enable or disable the feature, but cannot enable or disable the associated keyword. If you specify the -qkeyword=keyword_name option, the compiler reserves the keyword_name (constexpr, decltype, nullptr or static_assert) as a keyword, but the associated feature is not enabled automatically.

The following table demonstrates how the compiler behaves when different option settings are in effect.

Table 2. Compiler behaviour under different option settings

	-qkeyword=keyword_name enabled	-qnokeyword=keyword_name enabled
The -qlanglvl suboption or group option is enabled	The feature is enabled. keyword_name is reserved as a keyword.	The feature is enabled. keyword_name is reserved as a keyword. A warning message is issued to indicate that the -qnokeyword=keyword_name option is ignored.
Neither the -qlanglvl suboption nor group option is enabled	The feature is disabled. keyword_name is reserved as a keyword. An error message is issued in contexts where keyword_name should not be used while the keyword is reserved but the feature is disabled. You can either enable the feature by using the -qlanglvl suboption or group option or disable the keyword by using the -qnokeyword=keyword_name option.	The feature is disabled. keyword_name is treated as an identifier token. When the -qwarn0x option is enabled, a warning message is issued when it is expected that turning on the feature will modify the validity or semantics of the program.

Predefined macros

• __BOOL__ is defined to 1 by default; however, it is undefined when -qnokeyword=bool is in effect.
• __C99_INLINE is defined to 1 when -qkeyword=inline is in effect.
• __C99_RESTRICT is defined to 1 when -qkeyword=restrict is in effect.
• __IBM_GCC_ASM is defined to 1 when -qkeyword=asm is in effect. (In C++ it is defined by default.)
• __IBM__TYPEOF__ is defined to 1 when -qkeyword=typeof is in effect.

Related information

• -qwarn0x (C++11)