Developer Guide and Reference

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Proxy

Proxy object provides access to a specific Primitive, Primitive data member, or nested data member within a Primitive for an element in a container.
Description
accessor [index] or a Proxy object’s Data Member Interfaces return Proxy objects. That Proxy object represents the Primitive, Primitive data member, or nested data member within a Primitive for an element in a container. The Proxy object has the following features:
  • A value_type can be exported or imported from the Proxy.
    • Conversion operator is used to export the value_type
    • Alternatively the Proxy can be passed to the function
      unproxy
      to export a
      value_type
    • Assignment operator = is used to import value_type into the Proxy
  • Overloads the following operators if the underlying value_type supports the operator
    • ==, !=, <, >, <=, >=, +, -, *, /, %, &&, ||, &, |, ^, ~, *, +, -, !, +=, -=, *=, /=, %=, >>=, <<=, &=, |=, ^=, ++, --
    • When an operator is called the following occurs:
      • value_type is exported
      • The operator applied to the exported value
      • If the operator was an assignment, the result is imported back into the Member and returns the proxy
      • Otherwise a result is returned.
  • Data Member Interface.
    • For each data member of value_type
      • A member access method is defined which returns a Member proxy representing just that member.
Member Type
Description
typedef implementation-defined value_type
The type of the data the Proxy is representing
Member
Description
operator value_type const () const;
Returns: exports a copy of the Proxy’s value.
NOTE: constant return value prevents rvalue assignment for structs offering some protection against code that expected a modifiable reference.
const value_type & operator = (const value_type &a_value);
Imports a_value into container at the position the Proxy is representing.
Returns: the same constant value_type it was passed.
NOTE: This behavior is different from traditional assignment operators that return *this. Choice was to enable efficient chaining of assignment operators versus returning a Proxy which would have to export the value it had just imported.
Proxy & operator = (const Proxy &other);
Exports value from the other Proxy and imports it.
Returns: A reference to this Proxy obect.
auto name_of_values_data_member_1()const;
Returns: Proxy instance representing the 1st data member of the value_type
NOTE: actual method name is the name of the value_type’s 1st data member
auto name_of_values_data_member_2()const;
Returns: Proxy instance representing the 2nd data member of the value_type.
NOTE: actual method name is the name of the value_type’s 2nd data member.
auto name_of_values_data_member_...()const;
Returns: Proxy instance representing the ...th data member of the value_type.
NOTE: actual method name is the name of the value_type’s …th data member.
auto name_of_values_data_member_N()const;
Returns: Proxy instance representing the Nth data member of the value_type.
NOTE: actual method name is the name of the value_type’s Nth data member

Product and Performance Information

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Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.