Convert Swift CChar array into a String

Question

Some C APIs, e.g. glGetShaderInfoLog, return character arrays in buffers. I need to convert them to Strings to use them.

var value: GLint = 0
glGetShaderiv(shader, GLenum(GL_INFO_LOG_LENGTH), &value)
var infoLog: GLchar[] = GLchar[](count: Int(value), repeatedValue: 0)
var infoLogLength: GLsizei = 0
glGetShaderInfoLog(shader, value, &infoLogLength, &infoLog)
var s: String = NSString.stringWithUTF8String(infoLog) // Compile Error: Cannot convert the expression's type 'NSString!' to type 'CString'

In this example GLchar maps to the Swift type CChar AKA Int8 but for the life of me I can't find a String or NSString method that will initialize with it.

Answer 1

This does the trick:

var s = NSString(bytes: infoLog, length: Int(infoLogLength), encoding: NSASCIIStringEncoding)

Answer 2

Alternatively here is another option that compiles:

var infoLog = UnsafePointer<CChar>.alloc(Int(value))
glGetShaderInfoLog(shader, value, nil, infoLog)
var infoLogString = String.fromCString(infoLog)
infoLog.dealloc(Int(value))