interval_map<K, V> is a data structure that efficiently associates intervals of keys of type K with values of type V. It is implemented on top of std::map.
The assign member function is implemented as follows:
Each key-value-pair (K, V) in the std::map means that the value V is associated with the interval from K (including) to the next key (excluding) in the std::map.
The std::map (0,'A'), (3,'B'), (5,'A') represents the mapping:
- 0 -> 'A'
- 1 -> 'A'
- 2 -> 'A'
- 3 -> 'B'
- 4 -> 'B'
- 5 -> 'A'
- 6 -> 'A'
- 7 -> 'A'
- ... all the way to numeric_limits::max()
The representation in the std::map must be canonical, that is, consecutive map entries must not have the same value: ..., (0,'A'), (3,'A'), ... is not allowed. Initially, the whole range of K is associated with a given initial value, passed to the constructor of the interval_map<K, V> data structure.
- besides being copyable and assignable, is less-than comparable via operator<
- is bounded below, with the lowest value being std::numeric_limits::lowest()
- does not implement any other operations, in particular no equality comparison or arithmetic operators
- besides being copyable and assignable, is equality-comparable via operator==
- does not implement any other operations