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[Boost-sandbox-cvs] boost-sandbox/libs/units/doc units.qbk, 1.1.1.2, 1.2
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From: Matthias S. <mat...@us...> - 2007-04-12 18:09:05
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Update of /cvsroot/boost-sandbox/boost-sandbox/libs/units/doc In directory sc8-pr-cvs3.sourceforge.net:/tmp/cvs-serv14595/doc Modified Files: units.qbk Log Message: doc edits Index: units.qbk =================================================================== RCS file: /cvsroot/boost-sandbox/boost-sandbox/libs/units/doc/units.qbk,v retrieving revision 1.1.1.2 retrieving revision 1.2 diff -u -d -r1.1.1.2 -r1.2 --- units.qbk 20 Mar 2007 04:57:10 -0000 1.1.1.2 +++ units.qbk 12 Apr 2007 18:09:01 -0000 1.2 @@ -1,6 +1,6 @@ [library Boost.Units [quickbook 1.3] - [version 0.7.1] + [version 0.8.0] [authors [Schabel, Matthias C.]] [authors [Watanabe, Steven]] [copyright 2003-2007 Matthias Christian Schabel, 2007 Steven Watanabe] @@ -57,14 +57,16 @@ [section:Introduction Introduction] -The Boost.Units library is a C++ implementation of zero runtime overhead compile-time dimensional analysis in a general -and extensible manner, treating it as a generic metaprogramming problem. Support for units +The Boost.Units library is a C++ implementation of dimensional analysis in a general +and extensible manner, treating it as a generic compile-time metaprogramming problem. With appropriate +compiler optimization, no runtime execution cost is introduced, facilitating the use of this library to +provide dimension checking in performance-critical code. Support for units and quantities (defined as a unit and associated value) for arbitrary unit system models and arbitrary -value types is provided, as is a general facility for unit conversions enabling fine-grained control over -conversion. Complete SI and CGS unit system models are provided, along with systems for -angles measured in degrees, gradians, and radians. A small subset of the SI system including only length, mass, -and time is developed in the examples as a demonstration of the relative ease of adding new unit systems and -the extensibility of the library architecture. +value types is provided, as is a fine-grained general facility for unit conversions. Complete SI and CGS unit +systems are provided, along with systems for +angles measured in degrees, gradians and systems for temperatures measured in degrees Celsius or Fahrenheit. +The library architecture has been designed with flexibility and extensibility in mind; demonstrations of the ease +of adding new units and new unit systems are provided in the examples. In order to enable complex compile-time dimensional analysis calculations with no runtime overhead, Boost.Units relies heavily on the [___boost_mpl] (MPL) and on template metaprogramming techniques, and is, as a consequence, @@ -82,6 +84,7 @@ # Microsoft Visual C++ 6.0 on Windows XP # Microsoft Visual C++ 7.0 on Windows XP # Metrowerks CodeWarrior 8.0 on Windows XP. +# g++ 3.3.x [endsect] @@ -90,19 +93,23 @@ Before discussing the basics of the library, we first define a few terms that will be used frequently in the following : -* *Fundamental dimension* : A fundamental dimension is a type of measurement that forms the basis - of a unit system. The SI unit system defines seven fundamental dimensions : length \[L\], mass \[M\], time \[T\], - current \[C\], temperature \[K\], amount \[A\], and luminous intensity \[I\]. -* *Dimension* : A dimension represents the signature of a collection of fundamental dimensions, each - potentially raised to a different rational power. For example, area = \[L\]^2, velocity = \[L\]/\[T\], - energy = \[M\] \[L\]^2/\[T\]^2. -* *Unit* : Units are a specific measure of a dimension. While length is an abstract measure of - distance, the meter is the concrete unit of distance in the SI system. Units represent a reference - measure of some dimension (fundamental or otherwise). -* *Quantity* : Quantities represent a concrete amount of some unit. Thus, while the meter is a unit of length in the SI system, - 5.5 meters is a quantity of length in that system. +* *Base dimension* : A base dimension is defined as a measurable entity that forms a component of the basis + of a unit system. The SI unit system defines seven base dimensions : length \[L\], mass \[M\], time \[T\], + current \[I\], temperature \[theta\], amount \[N\], and luminous intensity \[J\]. +* *Derived dimension* : A collection of one or more base dimensions, each + potentially raised to a different rational power. For example, area = \[L\]^2, velocity = \[L\]/\[T\], and + energy = \[M\] \[L\]^2/\[T\]^2 are all derived dimensions. +* *Dimension* : The general term dimension is used to refer to either a base or a derived dimension. +* *Base unit* : A base unit represents a specific measure of a base dimension. While length is an abstract measure of + distance, the meter is the concrete base unit of distance in the SI system. +* *Derived unit* : Derived units represent a specific measure of a derived dimension. +* *Unit* : The general term unit is used to refer to either a base or a derived unit. +* *Base quantity* : A base quantity represents a concrete amount of a base unit. Thus, while the meter is the base + unit of length in the SI system, 5.5 meters is a base quantity of length in that system. +* *Derived quantity* : Derived quantities represent a concrete amount of a derived unit. +* *Quantity* : The general term quantity is used to refer to either a base or a derived quantity. -To begin, we present a short [@../example/tutorial.cpp tutorial] that demonstrates the use of +To begin, we present two short tutorials. [@../example/tutorial1.cpp Tutorial1] demonstrates the use of [@http://en.wikipedia.org/wiki/SI_units SI] units. After including the appropriate system headers and the headers for the various SI units we will need (all SI units can be included with [headerref boost/units/systems/si.hpp]) and for quantity I/O ([headerref boost/units/io.hpp]), we define |
