9 Declarations[Decl]

9.1 Preamble[Decl.Pre]

Declarations generally specify how names are to be interpreted. Declarations have the form

9.2 Specifiers[Decl.Spec]

9.2.1 General[Decl.Spec.General]

The specifiers that can be used in a declaration are

9.2.2 Function specifiers[Decl.Spec.Fct]

A function-specifier can be used only in a function declaration.

The export specifier denotes that the function has program linkage (6.7.1).

The export specifier cannot be used on functions directly or indirectly within an unnamed namespace.

Functions with program linkage can also be specified in export-declaration-group ([Decl.Export]).

If a function is declared with an export specifier then all redeclarations of the same function must also use the export specifier or be part of export-declaration-group ([Decl.Export]).

9.3 Declarators[Decl.Decl]

9.4 Initializers[Decl.Init]

The process of initialization described in this section applies to all initializers regardless of the context.

9.4.1 Aggregate Initialization[Decl.Init.Agg]

An aggregate is a vector, matrix, array, or class.

The subobjects of an aggregate have a defined order. For vectors and arrays the order is increasing subscript order. For matrices it is increasing subscript order with the subscript nesting such that in the notation Mat[M][N], the ordering is Mat[0][0]...Mat[0][N]...Mat[M][0]...Mat[M][N]. For classes the order is base class, followed by member subobjects in declaration order.

A flattened ordering of subobjects can be produced by performing a depth-first traversal of the subobjects of an object following the defined subobject ordering.

Each braced initializer list is comprised of zero or more initializer-clause expressions, which is either another braced initializer list or an expression which generates a value that either is or can be implicitly converted to an rvalue. Each assignment-expression is an object, which may be a scalar or aggregate type. A flattened initializer sequence is a sequence of expressions constructed by a depth-first traversal over each assignment-expression in an initializer-list and performing a depth-first traversal accessing each subobject of the assignment-expression.

If the target object is an array of unknown size, the object is assumed to have m possible elements during parsing, where m > 0.

An initializer-list is a valid initializer if for each element E_n mod  m in the target object’s flattened ordering there is a corresponding expression E_n in the flattened initializer sequence, which can be implicitly converted to the element’s type. For arrays of unknown size, the total number of expressions in the flattened initializer sequence must be a multiple of the array’s base element type.

An initializer-list is invalid if the flattened initializer sequence contains more or fewer elements than the target object’s flattened ordering, or if any initializer I_n cannot be implicitly converted to the corresponding element E_n’s type.