view dmd/complex_t.h @ 1317:4099548c80e0

Allocate objects on the stack if they (a) don't have a destructor, and (b) don't override the delete operator (on top of the regular conditions for stack allocation that also apply to arrays, structs, etc.). The "no destructor" clause is not strictly necessary, but calling them at the right time would be tricky to say the least; it would involve, among other things, "manually" inserting a try-finally block around anything that might throw exceptions not caught in the current function. Note: objects with custom new operators are automatically ignored because they don't use the regular allocation runtime call, so there's no need to pay special attention to them.
author Frits van Bommel <fvbommel wxs.nl>
date Sat, 09 May 2009 00:50:15 +0200
parents c53b6e3fe49a
children
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// Compiler implementation of the D programming language
// Copyright (c) 1999-2006 by Digital Mars
// All Rights Reserved
// written by Walter Bright and Burton Radons
// http://www.digitalmars.com
// License for redistribution is by either the Artistic License
// in artistic.txt, or the GNU General Public License in gnu.txt.
// See the included readme.txt for details.

#ifndef DMD_COMPLEX_T_H
#define DMD_COMPLEX_T_H

/* Roll our own complex type for compilers that don't support complex
 */

struct complex_t
{
    long double re;
    long double im;    

    complex_t() { this->re = 0; this->im = 0; }
    complex_t(long double re) { this->re = re; this->im = 0; }
    complex_t(long double re, long double im) { this->re = re; this->im = im; }

    complex_t operator + (complex_t y) { complex_t r; r.re = re + y.re; r.im = im + y.im; return r; }
    complex_t operator - (complex_t y) { complex_t r; r.re = re - y.re; r.im = im - y.im; return r; }
    complex_t operator - () { complex_t r; r.re = -re; r.im = -im; return r; }
    complex_t operator * (complex_t y) { return complex_t(re * y.re - im * y.im, im * y.re + re * y.im); }
    
    complex_t operator / (complex_t y)
    {
	long double abs_y_re = y.re < 0 ? -y.re : y.re;
	long double abs_y_im = y.im < 0 ? -y.im : y.im;
	long double r, den;

	if (abs_y_re < abs_y_im)
	{
	    r = y.re / y.im;
	    den = y.im + r * y.re;
	    return complex_t((re * r + im) / den,
			     (im * r - re) / den);
	}
	else
	{
	    r = y.im / y.re;
	    den = y.re + r * y.im;
	    return complex_t((re + r * im) / den,
			     (im - r * re) / den);
	}
    }

    operator bool () { return re || im; }

    int operator == (complex_t y) { return re == y.re && im == y.im; }
    int operator != (complex_t y) { return re != y.re || im != y.im; }
};

inline complex_t operator * (long double x, complex_t y) { return complex_t(x) * y; }
inline complex_t operator * (complex_t x, long double y) { return x * complex_t(y); }
inline complex_t operator / (complex_t x, long double y) { return x / complex_t(y); }


inline long double creall(complex_t x)
{
    return x.re;
}

inline long double cimagl(complex_t x)
{
    return x.im;
}

#endif