Things to avoid

Magic numbers, especially if they appear in more than one place. They really want to be named constants, but they also have to be named in a way that is not dependent on the actual value. For example, worldPopulation = 6,973,738,433.

The five (5) principles

... and here they are:

• Single responsibility!
• Open-closed! (but watch out for: single responsibility)
• Liskov substitution!
• Interface segregation! (see also: single responsibility)
• Dependency inversion!

No ParkHelper for you

FAIL:

../../../gcc-4.6.2/libjava/include/jvm.h:795:3: error: `ParkHelper' does not name a type

Compilers with C++11 support ...

C++11

Stdcxx wiki - C++0xCompilerSupport

C++0x/C++11 Support in GCC

Status of Experimental C++11 Support in GCC 4.7

Prerequisites for GCC

The GNU Multiple Precision Arithmetic Library (GMP)

The GNU MPFR Library (multiple-precision floating-point computations with correct rounding)

MPC (arithmetic of complex numbers with arbitrarily high precision and correct rounding)

configure: error: Building GCC requires GMP 4.2+, MPFR 2.3.1+ and MPC 0.8.0+.
Try the --with-gmp, --with-mpfr and/or --with-mpc options to specify their locations. Source code for these libraries can be found at their respective hosting sites as well as at ftp://gcc.gnu.org/pub/gcc/infrastructure/. See also http://gcc.gnu.org/install/prerequisites.html for additional info. If you obtained GMP, MPFR and/or MPC from a vendor distribution package, make sure that you have installed both the libraries and the header files. They may be located in separate packages.

GNU M4 (needed by gmp/configure: checking for suitable m4)

MPFR depends on GMP. The MPFR configure script may need help to find the GMP library and header files, e.g.

configure --with-gmp=/usr/local

(see INSTALL file).

MPC depends on MPFR and GMP. The MPC configure script can be informed about the whereabouts of gmp and mpfr, e.g.

configure --with-gmp=/usr/local --with-mpfr=/usr/local

(see INSTALL file).

The 0-1 principle, continued. The proof relies on using a monotonic mapping f which maps a pair of values a ≤ b onto a pair of values f(a) ≤ f(b). The idea is to choose f such that f(x) is either 0 or 1.

The o-1 principle: proof.

Leverage

1,168,107 (51.9%) vs 1,058,682 (47.1%) for a difference of 109,425 = 4.9% of a total of 2,249,026.