REALLOCATE
Reallocates storage for an existing reserved block of memory
Syntax:
Usage:
result = Reallocate( pointer, count )
pointer
The address of allocated memory to be reallocated.
count
The number of bytes, in total, to be reallocated.
Return Value:
The address of the reallocated memory. A null (0) pointer is returned if reallocation was unsuccessful, and the original memory pointed to by pointer remains unchanged.
Description:
Attempts to reallocate, or resize, memory previously allocated with
Allocate. The contents of the buffer are preserved, although if
count is less than the original size of the memory block, the buffer will be truncated.
If
pointer is null (
0), then
ReAllocate behaves identically to
Allocate.
Reallocated memory must be deallocated, or freed, with
Deallocate when no longer needed.
This function is not part of the
FreeBASIC runtime library, it is an alias for the C runtime library's
realloc, so it's not guaranteed to be thread safe in all platforms.
NOTE: Reallocating a pointer inside an object function, when that pointer contains the parent object of the function, is undefined, and will likely result in horrible crashes.
Dim a As Integer Ptr, b As Integer Ptr, i As Integer
a = Allocate( 5 * SizeOf(Integer) ) ' Allocate memory for 5 integers
If a = 0 Then Print "Error Allocating a": End
For i = 0 To 4
a[i] = (i + 1) * 2 ' Assign integers to the buffer
Next i
b = Reallocate( a, 10 * SizeOf(Integer) ) ' Reallocate memory for 5 additional integers
If b <> 0 Then
a = b
For i = 5 To 9
a[i] = (i + 1) * 2 ' Assign more integers to the buffer
Next i
For i = 0 To 9 ' Print the integers
Print i, a[i]
Next i
Print
Else '' Reallocate failed, memory unchanged
Print "Error Reallocating a"
For i = 0 To 4 ' Print the integers
Print i, a[i]
Next i
Print
End If
Deallocate a ' Clean up
Dialect Differences:
- Not available in the -lang qb dialect unless referenced with the alias __Reallocate.
Differences from QB:
See also:
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