copy_graph

Copies all vertices and edges from one graph into another, along with their properties.

Complexity: O(V + E)
Defined in: <boost/graph/copy.hpp>

copy_graph internally requires a vertex_index property map. With VertexList=listS, the call will not compile unless you supply your own vertex index.

Example

#include <iostream>
#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/copy.hpp>

int main() {
    using Graph = boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS>;
    Graph g;
    boost::add_edge(0, 1, g);
    boost::add_edge(1, 2, g);
    boost::add_edge(2, 3, g);

    Graph g_copy;
    boost::copy_graph(g, g_copy);

    std::cout << "Original: " << num_vertices(g) << " vertices, "
              << num_edges(g) << " edges\n";
    std::cout << "Copy:     " << num_vertices(g_copy) << " vertices, "
              << num_edges(g_copy) << " edges\n";
}

Original: 4 vertices, 3 edges
Copy:     4 vertices, 3 edges

(1) Named parameter version

template <class VertexListGraph, class MutableGraph,
          class P, class T, class R>
void copy_graph(
    const VertexListGraph& G, MutableGraph& G_copy,
    const bgl_named_params<P, T, R>& params);

Direction Parameter Description

Direction	Parameter	Description
IN	`const VertexListGraph& G`	A directed or undirected graph. The graph type must be a model of Vertex List Graph.
OUT	`MutableGraph& G_copy`	The resulting copy of the graph. The graph type must be a model of Mutable Graph.

const VertexListGraph& G

A directed or undirected graph. The graph type must be a model of Vertex List Graph.

OUT

MutableGraph& G_copy

The resulting copy of the graph. The graph type must be a model of Mutable Graph.

Named Parameters

Direction Parameter Description

Direction	Parameter	Description
IN	`vertex_copy(VertexCopier vc)`	This is a Binary Function that copies the properties of a vertex in the original graph into the corresponding vertex in the copy. Default: `vertex_copier<VertexListGraph, MutableGraph>` which uses the property tag `vertex_all` to access a property map from the graph.
IN	`edge_copy(EdgeCopier ec)`	This is a Binary Function that copies the properties of an edge in the original graph into the corresponding edge in the copy. Default: `edge_copier<VertexListGraph, MutableGraph>` which uses the property tag `edge_all` to access a property map from the graph.
IN	`vertex_index_map(VertexIndexMap i_map)`	The vertex index map type must be a model of Readable Property Map and must map the vertex descriptors of `G` to the integers in the half-open range `[0,num_vertices(G))`. Default: `get(vertex_index, G)`. Note: if you use this default, make sure your graph has an internal `vertex_index` property. For example, `adjacency_list` with `VertexList=listS` does not have an internal `vertex_index` property.
UTIL/OUT	`orig_to_copy(Orig2CopyMap c)`	This maps vertices in the original graph to vertices in the copy. Default: an iterator_property_map created from a `std::vector` of the output graph’s vertex descriptor type of size `num_vertices(g)` and using the `i_map` for the index map.

vertex_copy(VertexCopier vc)

This is a Binary Function that copies the properties of a vertex in the original graph into the corresponding vertex in the copy.
Default: vertex_copier<VertexListGraph, MutableGraph> which uses the property tag vertex_all to access a property map from the graph.

edge_copy(EdgeCopier ec)

This is a Binary Function that copies the properties of an edge in the original graph into the corresponding edge in the copy.
Default: edge_copier<VertexListGraph, MutableGraph> which uses the property tag edge_all to access a property map from the graph.

vertex_index_map(VertexIndexMap i_map)

The vertex index map type must be a model of Readable Property Map and must map the vertex descriptors of G to the integers in the half-open range [0,num_vertices(G)).
Default: get(vertex_index, G). Note: if you use this default, make sure your graph has an internal vertex_index property. For example, adjacency_list with VertexList=listS does not have an internal vertex_index property.

UTIL/OUT

orig_to_copy(Orig2CopyMap c)

This maps vertices in the original graph to vertices in the copy.
Default: an iterator_property_map created from a std::vector of the output graph’s vertex descriptor type of size num_vertices(g) and using the i_map for the index map.

(2) Positional version

template <class VertexListGraph, class MutableGraph>
void copy_graph(const VertexListGraph& G, MutableGraph& G_copy);

Equivalent to (1) with every named parameter left at its default. Uses the default vertex/edge copiers (via vertex_all / edge_all property tags) and get(vertex_index, G).

Direction Parameter Description

Direction	Parameter	Description
IN	`const VertexListGraph& G`	Same as (1).
OUT	`MutableGraph& G_copy`	Same as (1).

const VertexListGraph& G

Same as (1).

OUT

MutableGraph& G_copy

Same as (1).

Description

This function copies all of the vertices and edges from graph G into G_copy. Also, it copies the vertex and edge properties, either by using the vertex_all and edge_all property maps, or by user-supplied copy functions.

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