cpp_map: Create map

In cppcontainers: 'C++' Standard Template Library Containers

Create map

Description

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

Usage

cpp_map(keys, values)

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.

Value

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

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] 

cppcontainers documentation built on Sept. 9, 2025, 5:55 p.m.