Metal Shader Language reference

I'm looking for the MSL reference for matrix functions. The following matrix functions are listed:

Matrix Functions

The functions in this section are in the Metal standard library and are defined in the header

<metal_matrix>

• float determinant(floatnxn)

  half determinant(halfnxn)

  Computes the determinant of

  matrix

  , which must be a square matrix.

• floatmxn transpose(floatnxm)

  halfmxn transpose(halfnxm)

  Transpose

  matrix

  .

I guess the header is the right reference but I'm not able to locate it.

Where is metal_matrix header and all other metal headers?

I couldn't decipher this from the command xcode generates as well:

CompileMetalFile sample/Shaders.metal

cd metalsamples/sample

/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/usr/bin/metal -arch air64 -emit-llvm -c -gline-tables-only -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.11.sdk -ffast-math -serialize-diagnostics /Users/_name/Library/Developer/Xcode/DerivedData/sample-aefgcnngjrabhwdzalozuvcuywyu/Build/Intermediates/sample.build/Debug/sample.build/Metal/Shaders.dia -o /Users/_name/Library/Developer/Xcode/DerivedData/sample-aefgcnngjrabhwdzalozuvcuywyu/Build/Intermediates/sample.build/Debug/sample.build/Metal/Shaders.air -mmacosx-version-min=10.11 -std=osx-metal1.1 metalsamples/sample/Shaders.metal

Thanks