Char-to-int conversion in C++ -


in chapter 3.9.1 "safe conversions," stroustrup's programming, has code illustrate safe conversion int char , back. 

#include<iostream> #include<string> #include<vector> #include<algorithm> #include<cmath> using namespace std;  int main() {      char c='x';     int i1=c;     int i2='x';      char c2 = i1;      cout << c <<'<< i1 << ' << c2 << '\n';      return 0; }

it's supposed print x 120 xto screen.

however, can't work , i'm not sure why. result x1764834364x.

i 3 warnings (in xcode 6.3.1).

  • multi-character character constant.
  • character constant long type.
  • unused variable i2.

what causes this?

the problem here:

'<< i1 << '

the compiler gives warning (gcc @ least):

warning: character constant long type

it believes trying display single char (the content between apostrophes), in fact passing multiple chars. want add spaces, like

' ' << i1 << ' '

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