Filter
Top Products
:: C++ scope resolution operator. Defined on struct, union, and
class types.
::
Double colons also represent the GDB scope operator (see
“Expressions” (page 83)). Same precedence as ::, above.
If an operator is redefined in the user code, GDB usually attempts to invoke the
redefined version instead of using the original meaning.
9.4.1.2 C and C++ constants
GDB allows you to express the constants of C and C++ in the following ways:
• Integer constants are a sequence of digits. Octal constants are specified by a leading
'0' (that is zero), and hexadecimal constants by a leading '0x' or '0X'. Constants can
also end with a letter 'l', specifying that the constant should be treated as a long
value.
• Floating point constants are a sequence of digits, followed by a decimal point,
followed by a sequence of digits, and optionally followed by an exponent. An
exponent is of the form: 'e[[+]|-]nnn', where nnn is a sequence of digits. The
'+' is optional for positive exponents. A floating-point constant may also end with
a letter 'f' or 'F', specifying that the constant should be treated as being of the
float (as opposed to the default double) type; or with a letter 'l' or `L', which
specifies a long double constant.
• Enumerated constants consist of enumerated identifiers, or their integral
equivalents.
• Character constants are a single character surrounded by single quotes ('), or a
number or the ordinal value of the corresponding character (usually its ASCII
value). Within quotes, the single character may be represented by a letter or by
escape sequences, which are of the form '\nnn', where nnn is the octal representation
of the character's ordinal value; or of the form '\x', where 'x' is a predefined special
character―for example, '\n' for newline.
• String constants are a sequence of character constants surrounded by double quotes
("). Any valid character constant (as described above) may appear. Double quotes
within the string must be preceded by a backslash, so for instance '"a\"b'c"' is
a string of five characters.
• Pointer constants are an integral value. You can also write pointers to constants
using the C operator '&'.
• Array constants are comma-separated lists surrounded by braces '{' and '}'; for
example, '{1,2,3}' is a three-element array of integers, '{{1,2}, {3,4},
{5,6}}' is a three-by-two array, and '{&"hi", &"there", &"fred"}' is a
three-element array of pointers.
108 Using GDB with Different Languages