Type 7 – Floats & control tokens¶
This type combines two completely unrelated types of items – floating point numbers and special values such as true, false, null, etc. We refer to these special values as ‘control values’ or ‘ctrls’ for short throughout the code.
Just like integers, they have different possible width (resulting in different value ranges and precisions).
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enum
cbor_float_width¶ Possible widths of CBOR_TYPE_FLOAT_CTRL items.
Values:
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CBOR_FLOAT_0¶ Internal use - ctrl and special values.
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CBOR_FLOAT_16¶ Half float.
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CBOR_FLOAT_32¶ Single float.
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CBOR_FLOAT_64¶ Double.
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Corresponding cbor_type |
CBOR_TYPE_FLOAT_CTRL |
| Number of allocations | One per lifetime |
| Storage requirements | sizeof(cbor_item_t) + 1/4/8 |
Getting metadata¶
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bool
cbor_float_ctrl_is_ctrl(const cbor_item_t *item)¶ Is this a ctrl value?
- Return
- Is this a ctrl value?
- Parameters
item[borrow]-A float or ctrl item
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cbor_float_width
cbor_float_get_width(const cbor_item_t *item)¶ Get the float width.
- Return
- The width.
- Parameters
item[borrow]-A float or ctrl item
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bool
cbor_ctrl_is_bool(const cbor_item_t *item)¶ Is this ctrl item a boolean?
- Return
- Is this ctrl item a boolean?
- Parameters
item[borrow]-A ctrl item
Reading data¶
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float
cbor_float_get_float2(const cbor_item_t *item)¶ Get a half precision float.
The item must have the corresponding width
- Return
- half precision value
- Parameters
borrow]-A half precision float
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float
cbor_float_get_float4(const cbor_item_t *item)¶ Get a single precision float.
The item must have the corresponding width
- Return
- single precision value
- Parameters
borrow]-A signle precision float
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double
cbor_float_get_float8(const cbor_item_t *item)¶ Get a double precision float.
The item must have the corresponding width
- Return
- double precision value
- Parameters
borrow]-A double precision float
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double
cbor_float_get_float(const cbor_item_t *item)¶ Get the float value represented as double.
Can be used regardless of the width.
- Return
- double precision value
- Parameters
borrow]-Any float
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uint8_t
cbor_ctrl_value(const cbor_item_t *item)¶ Reads the control value.
- Return
- the simple value
- Parameters
item[borrow]-A ctrl item
Creating new items¶
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cbor_item_t *
cbor_new_ctrl()¶ Constructs a new ctrl item.
The width cannot be changed once the item is created
- Return
- new 1B ctrl
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cbor_item_t *
cbor_new_float2()¶ Constructs a new float item.
The width cannot be changed once the item is created
- Return
- new 2B float
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cbor_item_t *
cbor_new_float4()¶ Constructs a new float item.
The width cannot be changed once the item is created
- Return
- new 4B float
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cbor_item_t *
cbor_new_float8()¶ Constructs a new float item.
The width cannot be changed once the item is created
- Return
- new 8B float
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cbor_item_t *
cbor_new_null()¶ Constructs new null ctrl item.
- Return
- new null ctrl item
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cbor_item_t *
cbor_new_undef()¶ Constructs new under ctrl item.
- Return
- new under ctrl item
Building items¶
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cbor_item_t *
cbor_build_bool(bool value)¶ Constructs new boolean ctrl item.
- Return
- new boolen ctrl item
- Parameters
value-The value to use
Manipulating existing items¶
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void
cbor_set_ctrl(cbor_item_t *item, uint8_t value)¶ Assign a control value.
Warning
It is possible to produce an invalid CBOR value by assigning a invalid value using this mechanism. Please consult the standard before use.
- Parameters
item[borrow]-A ctrl item
value-The simple value to assign. Please consult the standard for allowed values
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void
cbor_set_float2(cbor_item_t *item, float value)¶ Assigns a float value.
- Parameters
item[borrow]-A half precision float
value-The value to assign
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void
cbor_set_float4(cbor_item_t *item, float value)¶ Assigns a float value.
- Parameters
item[borrow]-A single precision float
value-The value to assign
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void
cbor_set_float8(cbor_item_t *item, double value)¶ Assigns a float value.
- Parameters
item[borrow]-A double precision float
value-The value to assign