Type Conversion Functions

Collaboration diagram for Type Conversion Functions:

Modules
	String Type Constants
	String type constants as returned by type() and typename()

Namespaces
	Qore::Type
	Type namespace.

Functions
auto	Qore::auto_cast (auto val)
	Returns complex types converted to the most specific types possible using internal type folding. More...
binary	Qore::binary ()
	Always returns an empty binary object (of zero length) More...
binary	Qore::binary (null x)
	Always returns an empty binary object (of zero length) More...
binary	Qore::binary (softstring str)
	Returns a binary data type of the string passed; data types other than string will first be converted to a string and then returned as binary data. More...
binary	Qore::binary (binary bin)
	Always returns the same binary object passed. More...
string	Qore::binary_to_string (binary b, *string encoding)
	Returns a string created from the binary data passed, taking an optional second argument giving the string encoding; if no second argument is passed then the default character encoding is assumed. More...
bool	Qore::boolean (any arg)
	Converts the argument to a boolean value. More...
float	Qore::float (softfloat f)
	Converts the argument to a floating-point (float) value. More...
float	Qore::float ()
	Always returns 0.0. More...
hash< auto >	Qore::hash (object obj)
	Returns a hash of an object's members. More...
hash< auto >	Qore::hash (list< auto > l)
	Returns a hash by taking even numbered list elements (starting with 0) and converting them to strings for the hash keys, and the odd numbered elements following the keys as the key value. More...
hash< auto >	Qore::hash (list< softstring > keys, list< auto > values)
	Returns a hash by taking the first list as a list of keys, and the second list as a list of values. More...
hash	Qore::hash (hash h)
	Returns the same hash with all complex types stripped. More...
hash< auto >	Qore::hash ()
	Always returns the same hash passed. More...
int	Qore::int (string str, int base=10)
	Converts the string to an integer value with respect to the base. More...
int	Qore::int (softint i)
	Converts the argument to an integer value. More...
int	Qore::int ()
	Always returns 0. More...
list< auto >	Qore::list (...)
	Returns a list of the arguments passed at the top level. More...
number	Qore::number (softnumber n)
	Converts the argument to a number value. More...
number	Qore::number ()
	Always returns 0.0. More...
string	Qore::string (softstring str, *string enc)
	Converts the argument to a string. More...
string	Qore::string ()
	Always returns an empty string. More...
string	Qore::type (auto arg)
	Returns a string giving the data type of the argument passed; see String Type Constants for the values returned by this function. More...
string	Qore::typename (auto arg)
	Returns a string giving the data type of the argument passed; see String Type Constants for the values returned by this function. More...

Detailed Description

Function Documentation

auto_cast()

auto Qore::auto_cast

(

auto

val

)

Returns complex types converted to the most specific types possible using internal type folding.

Code Flags:

CONSTANT

Example:

list<auto> tmp;
tmp += 1;
tmp += 2;
list<int> int_list = auto_cast(tmp);

Parameters

val	the value to convert

Returns

a copy of the input value with complex types converted to the most specific types possible using internal type folding

Since

Qore 0.9.3

binary() [1/4]

binary Qore::binary

(

)

Always returns an empty binary object (of zero length)

Code Flags:

CONSTANT

The binary() function is used for type conversions, therefore this variant is not tagged with NOOP

See also

• binary(softstring)
• binary(null)

binary() [2/4]

binary Qore::binary

(

binary

bin

)

Always returns the same binary object passed.

Code Flags:

CONSTANT

The binary() function is used for type conversions, therefore this variant is not tagged with NOOP

binary() [3/4]

binary Qore::binary

(

null

x

)

Always returns an empty binary object (of zero length)

Code Flags:

CONSTANT

The binary() function is used for type conversions, therefore this variant is not tagged with NOOP

See also

binary(softstring)

binary() [4/4]

binary Qore::binary

(

softstring

str

)

Returns a binary data type of the string passed; data types other than string will first be converted to a string and then returned as binary data.

This function is useful if, for example, a string type actually contains binary data; using this function will ensure that all data in the string (even if it contains embedded nulls) is maintained in the binary object (Qore strings must normally be terminated by a single null, so some Qore string operations do not work on binary data with embedded nulls).

Code Flags:

CONSTANT

Example:

binary b = binary(str);

See also

<string>::toBinary()

binary_to_string()

string Qore::binary_to_string	(	binary	b,
		*string	encoding
	)

Returns a string created from the binary data passed, taking an optional second argument giving the string encoding; if no second argument is passed then the default character encoding is assumed.

Code Flags:

CONSTANT

Parameters

b	the binary object to convert directly to a string
encoding	the character encoding tag for the string return value; if not present, the default character encoding is assumed

Returns

a string created from the binary data passed

Example:

string str = binary_to_string(b, "iso-8859-1");

boolean()

bool Qore::boolean

(

any

arg

)

Converts the argument to a boolean value.

Code Flags:

CONSTANT

Parameters

arg	the argument to convert to a boolean

Returns

the boolean value corresponding to the argument

Example:

bool b = boolean(1); # returns True

Note

this function behaves differently when %strict-bool-eval is set

float() [1/2]

float Qore::float

(

)

Always returns 0.0.

Code Flags:

CONSTANT

The float() function is used for type conversions, therefore this variant is not tagged with NOOP

See also

float(softfloat)

float() [2/2]

float Qore::float

(

softfloat

f

)

Converts the argument to a floating-point (float) value.

Code Flags:

CONSTANT

Parameters

f	the argument to convert to a float

Returns

the float value corresponding to the argument

Example:

float i = float("3.1415");

hash() [1/5]

hash<auto> Qore::hash

(

)

Always returns the same hash passed.

Code Flags:

CONSTANT

The hash() function is used for type conversions, therefore this variant is not tagged with NOOP

hash() [2/5]

hash Qore::hash

(

hash

h

)

Returns the same hash with all complex types stripped.

Code Flags:

CONSTANT

Example:

hash h2 = hash(h1);

Parameters

h	the hash to return

Returns

the same hash passed as an argument with all complex types stripped

Since

• Qore 0.8.13 this function was modified to remove type information at runtime from typed hashes

hash() [3/5]

hash<auto> Qore::hash

(

list< auto >

l

)

Returns a hash by taking even numbered list elements (starting with 0) and converting them to strings for the hash keys, and the odd numbered elements following the keys as the key value.

Code Flags:

RET_VALUE_ONLY

Parameters

l	the list to process in a manner similar to perl's hash initialization

Returns

a hash by taking even numbered list elements (starting with 0) and converting them to strings for the hash keys, and the odd numbered elements following the keys as the key value

Example:

hash<auto> h = hash(("a", 1, "b", "two"));

hash() [4/5]

hash<auto> Qore::hash	(	list< softstring >	keys,
		list< auto >	values
	)

Returns a hash by taking the first list as a list of keys, and the second list as a list of values.

If the two lists are of unequal sizes, then the keys list takes precedence (if the values list is longer, excess values are ignored, if the keys list is longer, then excess elements are assigned NOTHING)

Code Flags:

RET_VALUE_ONLY

Parameters

keys	a list of key values for the hash
values	a list of values for the hash, corresponding to the elements in keys

Returns

a hash by taking the first list as a list of keys, and the second list as a list of values

Example:

hash<auto> h = hash(keysv, values);

hash() [5/5]

hash<auto> Qore::hash

(

object

obj

)

Returns a hash of an object's members.

Note

that if this function is called from outside the class' scope, the hash will only contain the object's public members

Code Flags:

RET_VALUE_ONLY

Parameters

obj	the object to process

Returns

a hash of an object's members

Example:

hash<auto> h = hash(obj);

int() [1/3]

int Qore::int

(

)

Always returns 0.

Code Flags:

CONSTANT

The int() function is used for type conversions, therefore this variant is not tagged with NOOP

See also

int(softint)

int() [2/3]

int Qore::int

(

softint

i

)

Converts the argument to an integer value.

Code Flags:

CONSTANT

Parameters

i	the argument to convert to an integer

Returns

the integer value corresponding to the argument

Example:

int i = int("1");

int() [3/3]

int Qore::int	(	string	str,
		int	base = 10
	)

Converts the string to an integer value with respect to the base.

If a character is out of range of the corresponding base only the substring preceeding the character is taken into account.
Base 0 means to interpret as a code literal, so that the actual base is 8, 10, or 16.
(Does the same as <string>::toInt(int base)).

Code Flags:

RET_VALUE_ONLY

Parameters

str	the string to convert to an integer
base	the base of the integer in the string; this value must be 0 or 2 - 36 inclusive or an INVALID-BASE exception will be thrown

Returns

the integer value corresponding to the arguments

Example:

int("fe", 16);   // returns 254
int("34", 5);    // returns 19
int("2p", 25);   // returns 2  (p means 25, which is out of range)
int("2p", 26);   // returns 77
int("2z", 36);   // returns 107
int("21");       // returns 21 (base = 10)
int("21", 0);    // returns 21 (base = 10)
int("021", 0);   // returns 17 (base =  8)
int("0x21", 0);  // returns 33 (base = 16)

Exceptions

INVALID-BASE

the base is invalid; must be 0 or 2 - 36 inclusive

See also

<string>::toInt(int base)

Since

Qore 0.8.5, this variant with the base argument is supported

list()

list<auto> Qore::list

(

...

)

Returns a list of the arguments passed at the top level.

Code Flags:

CONSTANT

Parameters

...	the arguments that will be returned as a list

Returns

a list of the arguments passed at the top level; if a sole argument of NOTHING is passed, then an empty list is returned

Example:

list<auto> l = list(1, 2, 3, 4);

number() [1/2]

number Qore::number

(

)

Always returns 0.0.

Code Flags:

CONSTANT

The number() function is used for type conversions, therefore this variant is not tagged with NOOP

See also

number(softnumber)

number() [2/2]

number Qore::number

(

softnumber

n

)

Converts the argument to a number value.

Code Flags:

CONSTANT

Parameters

n	the argument to convert to a number

Returns

the number value corresponding to the argument

Example:

number n = number("2.23040945718005e35");

string() [1/2]

string Qore::string

(

)

Always returns an empty string.

Code Flags:

CONSTANT

The string() function is used for type conversions, therefore this variant is not tagged with NOOP

See also

string(softstring)

string() [2/2]

string Qore::string	(	softstring	str,
		*string	enc
	)

Converts the argument to a string.

Code Flags:

CONSTANT

Parameters

str	the argument to convert to a string
enc	the encoding of the string returned

Returns

the string value corresponding to the argument(s)

Example:

string str = string(100);

Since

the enc argument was added in Qore 0.8.12

type()

string Qore::type

(

auto

arg

)

Returns a string giving the data type of the argument passed; see String Type Constants for the values returned by this function.

Code Flags:

CONSTANT

Parameters

arg	the argument to check

Returns

a string giving the data type of the argument passed; see String Type Constants for the values returned by this function

Example:

string type = type(v);

Note

• This function is identical to typename(any) and to calling pseudo-method <value>::type()
• It is faster and more efficient to use <value>::typeCode() for comparing data types

See also

pseudo-method <value>::typeCode()

typename()

string Qore::typename

(

auto

arg

)

Returns a string giving the data type of the argument passed; see String Type Constants for the values returned by this function.

Code Flags:

CONSTANT

Parameters

arg	the argument to check

Returns

a string giving the data type of the argument passed; see String Type Constants for the values returned by this function

Example:

string type = typename(v);

Note

• This function is identical to type(any) and to calling pseudo-method <value>::type()
• It is faster and more efficient to use <value>::typeCode() for comparing data types