foo.cpp

// xcrun clang++ -std=c++11 -stdlib=libc++

#include <tuple>
#include <iostream>

using namespace std;

tuple<int, int> minmax(int x, int y)
{
  if (x <= y) 
    return { x, y} 
  else 
    return { y, x };
}

int main(int argc, char* argv[])
{

  int a, b;

  tie(a, b) = minmax(10, 20);

  cout << "a = " << a << ", b = " << b << endl;

  return 0;
}

gistfile1.txt

biggie:tmp joelr$ xcrun clang++ -std=c++11 -stdlib=libc++ foo.cpp 
foo.cpp:11:12: error: chosen constructor is explicit in copy-initialization
    return { x, y} 
           ^~~~~~~
/Applications/Xcode45-DP1.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/c++/v1/tuple:569:9: note: 
      constructor declared here
        tuple(_Up&&... __u)
        ^
foo.cpp:13:12: error: chosen constructor is explicit in copy-initialization
    return { y, x };
           ^~~~~~~~
/Applications/Xcode45-DP1.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/c++/v1/tuple:569:9: note: 
      constructor declared here
        tuple(_Up&&... __u)
        ^
2 errors generated.