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e54ede1993
Restructuring parts of the user's guide. Removed some concepts and fixed issues with others. Added (incomplete) adjacency_matrix docs. [SVN r55976]
81 lines
2.6 KiB
Plaintext
81 lines
2.6 KiB
Plaintext
[/
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/ Copyright (C) 2007-2009 Andrew Sutton
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/
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/ Distributed under the Boost Software License, Version 1.0. (See accompanying
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/ file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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/]
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[/ TODO: This concept is fundamentally broken. It's trying to capture the
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/ association of named constants with a type or a particular use. We probably
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/ need to explore the design space of named concepts before we can really
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/ attribute this as a legitimate operation.
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/
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/ For example, why are these required to be scoped? Why not simply use the
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/ functions zero<T>() and infinity<T>()?
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/]
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[section Numeric Value]
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The [NumericValue] concept describes requirements for a type to behave
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as if it were numeric. This concept is generally used by algorithms that
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typically operate on numeric types, but can be specialized to operate on
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user-defined numerics or discrete types that emulate numerics.
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This concept requires that its models be regular (i.e., default and copy
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constructible, assignable, and equality comparable). Additioanlly, this
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concept requires all common mathematical operators (i.e., addition, subtraction,
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multiplication and division).
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Finally, this concept requires that its models define appropriate values of
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zero and infinity. These are used within certain computations to represent
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infinite and zero states.
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[heading Notation]
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The following expressions are used within this document:
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[table
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[[Expression] [Description]]
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[[N] [A type modeling the [NumericValue] concept.]]
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]
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[heading Associated Types]
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[table
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[[Name] [Type] [Description]]
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[
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[Value Type]
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[`numeric_value<N>::value_type`]
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[
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The underlying type of the numeric value.
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*Requirements:* `N` is a [NumericValue], and the `value_type`
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and `N` must be the same type.
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]
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]
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]
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[heading Expressions]
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[table
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[[Name] [Expression] [Result Type] [Description]]
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[
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[Zero Value]
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[`numeric_value<N>::zero()`]
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[`numeric_value<N>::value_type`]
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[
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Returns the zero-value of the numeric type.
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]
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]
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[
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[Infinite Value]
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[`numeric_value<N>::infinity()`]
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[`numeric_value<N>::value_type`]
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[
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Returns the designated value of infinity for the numeric type.
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*Notes:* Some types such as `float` and `double` have values
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that represent infinity. For other types, this must be explicitly
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designated. For built-in integral types this is often chosen to
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be `std::numeric_limits<N>::max()`.
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]
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]
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]
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[endsect]
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