string_physical_type

How a string is represented in memory.

Declaration

Syntax

string_physical_type = DescriptorString | CChar

Values

Value	Meaning
DescriptorString	a descriptor, {char* data, int64 size, int64 capacity}. The length and the capacity travel with the data, so the value can be reallocated and its length asked for.
CChar	a bare char*, the representation C uses and the one the string runtime functions take.

Return values

None. An enumeration value is not evaluated.

Description

The physical type is separate from the logical type: both representations hold the same characters. StringPhysicalCast moves between them, taking the data pointer out of a descriptor in one direction and wrapping a pointer in a descriptor with size and capacity set to -1 in the other, marking a string that must not be extended.

A local variable may not have the CChar physical type: the verifier rejects it, because a local string owns its storage and needs a descriptor to describe it.

See Also

String, StringPhysicalCast, array_physical_type