65 lines
2 KiB
C++
65 lines
2 KiB
C++
/* @file dimension.hpp */
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#pragma once
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#include <cstdint>
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namespace xo {
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namespace qty {
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/** @enum dimension
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* @brief represent an abstract dimension.
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*
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* *xo-unit* units are expressed as a cartesian product
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* of powers of these dimensions.
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**/
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enum class dimension {
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/** sentinel value. not a dimension **/
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invalid = -1,
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/** weight. native unit = 1 gram **/
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mass,
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/** distance. native unit = 1 meter **/
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distance,
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/** time. native unit = 1 second **/
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time,
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/** a currency amount. native unit depends on actual currency.
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* For USD: one US dollar.
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*
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* NOTE: multicurrency work not supported by *xo-unit*.
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* - (1usd + 1eur) is well-defined.
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* - (1sec + 1m) is not.
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**/
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currency,
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/** A screen price.
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* The interpretation of prices is highly context dependent;
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* expect useful to bucket separately from currenty amounts.
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**/
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price,
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/** not a dimension. comes last, counts entries **/
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n_dim
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};
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using dim = dimension;
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/** @brief string value for a dimension enum **/
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inline const char *
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dim2str(dimension x)
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{
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switch(x) {
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case dimension::mass: return "mass";
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case dimension::distance: return "distance";
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case dimension::time: return "time";
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case dimension::currency: return "currency";
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case dimension::price: return "price";
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default: break;
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}
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return "?dim";
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}
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/** @brief number of built-in dimensions, convenient for array sizing **/
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static constexpr std::size_t n_dim = static_cast<std::size_t>(dimension::n_dim);
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} /*namespace qty*/
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} /*namespace xo*/
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/* end dimension.hpp */
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