[swift-users] Why does the withUnsafeMutableBufferPointer closure take an inout parameter?

Martin R martinr448 at gmail.com
Sun Oct 8 14:14:26 CDT 2017

I wonder why the closure in the Array method

    mutating func withUnsafeMutableBufferPointer<R>(_ body: (inout UnsafeMutableBufferPointer<Array.Element>) throws -> R) rethrows -> R

takes an _inout_ parameter. The closure is called with a pointer to the contiguous array storage, and I fail to imagine an example where it makes sense to assign a new value to the parameter.

Any insights are welcome!

Regards, Martin

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