[SR-371] Swift needs better interoperation between char * const _[] and UnsafePointer<UnsafeMutablePointer<Int8>>

[swift-ci]

Previous ID	SR-371
Radar	None
Original Reporter	djs-code (JIRA User)
Type	Improvement

Additional Detail from JIRA

Votes	0
Component/s	Compiler, Standard Library
Labels	Improvement
Assignee	None
Priority	Medium

md5: 9fef48dfcb05d6f5109d915a1154149d

Issue Description:

Swift currently doesn't provide good facilities for passing arguments to methods that take in char * const _[] in C, which get mapped to UnsafePointer<UnsafeMutablePointer<Int8>>. The closest solution I've found (https://www.reddit.com/r/swift/comments/3r5027/char_in_swift/) requires some legwork.

let arguments = ["bash", "-c", "echo foo"]

let argv: UnsafeMutablePointer<UnsafeMutablePointer<CChar>> = arguments.withUnsafeBufferPointer {
let buffer = UnsafeMutablePointer<UnsafeMutablePointer<CChar>>.alloc($0.count + 1)
buffer.initializeFrom($0.map { $0.withCString(strdup) })
buffer[$0.count] = nil
return buffer
}

Whether it be done in the compiler or through new APIs in the standard library, there really should be a better solution for this.