Converting a C char array to a String

The C array char name[8] is imported to Swift as a tuple:

(Int8, Int8, Int8, Int8, Int8, Int8, Int8, Int8)

The address of name is the same as the address of name[0], and
Swift preserves the memory layout of structures imported from C, as
confirmed by Apple engineer Joe Groff:

… You can leave the struct defined in C and import it into Swift. Swift will respect C’s layout.

As a consequence, we can pass the address of record.name,
converted to an UInt8 pointer, to
the String initializer. The following code has been updated for Swift 4.2 and later:

let record = someFunctionReturningAStructRecord()
let name = withUnsafePointer(to: record.name) {
    $0.withMemoryRebound(to: UInt8.self, capacity: MemoryLayout.size(ofValue: $0)) {
        String(cString: $0)
    }
}

NOTE: It is assumed that the bytes in name[] are a valid NUL-terminated UTF-8 sequence.

For older versions of Swift:

// Swift 2:
var record = someFunctionReturningAStructRecord()
let name = withUnsafePointer(&record.name) {
    String.fromCString(UnsafePointer($0))!
}

// Swift 3:
var record = someFunctionReturningAStructRecord()
let name = withUnsafePointer(to: &record.name) {
    $0.withMemoryRebound(to: UInt8.self, capacity: MemoryLayout.size(ofValue: record.name)) {
        String(cString: $0)
    }
}

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