`copy_graph`

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

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.
### Where Defined

`boost/graph/copy.hpp`

### Parameters

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.

### Named Parameters

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.

### Complexity

The time complexity is *O(V + E)*.