C++11 lambda: mixed capture list

Question

Can somebody please show me examples of the following:

1) Lambda that captures x by value. y by reference. What do the rest default to, if unspecified?

2) Lambda that captures x by value. y by reference, all else by value.

3) Lambda that captures x by value. y by reference, all else by reference.

Also, is it allowed that 2 lambdas in the same scope have the same capture signature, such as both be [], or both be [&x, =]

Thanks

Answer 1

1) [x, &y](){} rest is not captured

2) [=, &y](){}

3) [&, x](){}

The capture-list is a comma-separated list of zero or more captures, optionally beginning with the capture-default. The only capture defaults are & (by reference) and = (by value). If a capture-default is used, no other captures may use the same capture type. Any capture may appear only once.

Also, is it allowed that 2 lambdas in the same scope have the same capture signature, such as both be [], or both be [&x, =]

Of course it is allowed. Every lambda will be distinct object and have its distinct type. If you capture variable by value in two lambdas, then every lambda will have its copy. If you capture variable by reference in two lambdas, then every lambda will have a reference to the same captured variable.