param::param (4 of 4 overloads)

Constructor.

Synopsis

template<
    class OptionalString>
param(
    string_view key,
    OptionalString const& value);

Description

This constructs a parameter with a key and value. No validation is performed on the strings. Ownership of the key and value is acquired by making copies.

Example

param qp( "key", "value" );

param qp( "key", optional<string_view>("value") );

param qp( "key", boost::none );

param qp( "key", nullptr );

param qp( "key", no_value );

Postconditions

this->key == key && this->value == value && this->has_value == true

Complexity

Linear in key.size() + value.size().

Exception Safety

Calls to allocate may throw.

Template Parameters

Type	Description
`OptionalString`	An optional string type, such as `string_view`, `std::nullptr`, `no_value_t`, or `optional<string_view>`.

Parameters

Name	Description
`key`, `value`	The key and value to set.