cppcontainers (version 1.0.4)

cpp_map: Create map

Description

Create a map. Maps are key-value pairs sorted by unique keys.

Usage

cpp_map(keys, values)

Value

Returns a CppMap object referencing a map in C++.

Arguments

keys

An integer, numeric, character, or logical vector.

values

An integer, numeric, character, or logical vector.

Details

Maps are associative containers. They do not provide random access through an index. I.e. m[2] does not return the second element.

C++ map methods implemented in this package are at, clear, contains, count, emplace, empty, erase, insert, insert_or_assign, max_size, merge, size, and try_emplace. The package also adds the == and [ operators and various helper functions (print, to_r, type).

All object-creating methods in this package begin with cpp_ to avoid clashes with functions from other packages, such as utils::stack and base::vector.

See Also

cpp_unordered_map, cpp_multimap, cpp_unordered_multimap.

Examples

m <- cpp_map(4:6, seq.int(1, by = 0.5, length.out = 3L))
m
# [4,1] [5,1.5] [6,2]

insert(m, seq.int(100, by = 0.1, length.out = 3L), 14:16)
m
# [4,1] [5,1.5] [6,2] [14,100] [15,100.1] [16,100.2]

print(m, from = 6L)
# [6,2] [14,100] [15,100.1] [16,100.2]

m <- cpp_map(c("world", "hello", "there"), 4:6)
m
# ["hello",5] ["there",6] ["world",4]

erase(m, "there")
m
# ["hello",5] ["world",4]