Ada Reference Manual (Ada 2022) — Legal Information

# H.1 Pragma Normalize_Scalars

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This pragma ensures that an otherwise uninitialized scalar object is set to a predictable value, but out of range if possible.

#### Syntax

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The form of a pragma Normalize_Scalars is as follows:
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pragma Normalize_Scalars;

#### Post-Compilation Rules

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Pragma Normalize_Scalars is a configuration pragma. It applies to all compilation_units included in a partition.

#### Documentation Requirements

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If a pragma Normalize_Scalars applies, the implementation shall document the implicit initial values for scalar subtypes, and shall identify each case in which such a value is used and is not an invalid representation.

#### Implementation Advice

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Whenever possible, the implicit initial values for a scalar subtype should be an invalid representation (see 13.9.1).
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NOTE 1 The initialization requirement applies to uninitialized scalar objects that are subcomponents of composite objects, to allocated objects, and to stand-alone objects. It also applies to scalar out parameters. Scalar subcomponents of composite out parameters are initialized to the corresponding part of the actual, by virtue of 6.4.1.
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NOTE 2 The initialization requirement does not apply to a scalar for which pragma Import has been specified, since initialization of an imported object is performed solely by the foreign language environment (see B.1).
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NOTE 3 The use of pragma Normalize_Scalars in conjunction with Pragma Restrictions(No_Exceptions) can result in erroneous execution (see H.4).

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