# proportional split¶

[algorithms.proportional_split]

Type of an argument for a proportional splitting constructor of Range.

An argument of type proportional_split may be used by classes that satisfies Range requirements to distinguish a proportional splitting constructor from a basic splitting constructor and from a copy constructor, and to suggest a ratio in which a particular instance of the class should be split.

// Defined in header <tbb/blocked_range.h>

namespace tbb {
class proportional_split {
public:
proportional_split(std::size_t _left = 1, std::size_t _right = 1);

std::size_t left() const;
std::size_t right() const;

operator split() const;
};
}


## Member functions¶

proportional_split(std::size_t _left = 1, std::size_t _right = 1)

Constructs a proportion with the ratio specified by coefficients _left and _right.

std::size_t left() const

Returns size of the left part of the proportion.

std::size_t right() const

Returns size of the right part of the proportion.

operator split() const

Makes proportional_split implicitly convertible to split type to use with ranges that do not support proportional splitting.