Chapter 1

In v7.0, the structure of ROM images was changed so that a single ROM can support more
than one locale. This is intended to make it easier for Symbian OS licensees to produce
ROMs for closely related locales.
Quick selection table
This table lists the most frequently used collection types, and shows the key distinctions
among them.
Class name Frequency of
insertions and
deletions
Array
length
Access
type
TArray Never Any Random T
TFixedArray
Infrequent Fixed Random T
RPointerArray Infrequent Bounded Random T*
RArray Infrequent Bounded Random T
Data
types
RArray Infrequent Bounded Random TInt
RArray Infrequent Bounded Random TUint
CArrayFixSeg Frequent Unbounded Random T
CArrayPtrSeg Frequent Unbounded Random T*
TSglQue Frequent Unbounded Sequential, T
single
direction
TDblQue Frequent Unbounded Sequential, T
both
directions
CDesCArrayFlat Infrequent Bounded Random Any 16-bit
descriptor
CDesCArraySeg Frequent Unbounded Random Any 16-bit
descriptor
CPtrCArray Infrequent Bounded Random TPtrC16
In a multiple-locale ROM, most files will be identical for all locales supported, even the
language-specific ones, such as resource files (assuming that the languages are closely
related). In this case, to keep the ROM size down to a minimum, it makes sense to store a
single copy of the common files, and only duplicate the files that are different.
To enable this, the ability to set a language downgrade path was added. The language
downgrade path is used when a language-specific file cannot be found for the ROM locale; it
specifies which languages can provide an alternative version.