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< html >< head >< title > boost::mpl::Integral Constant</ title >
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< h1 >< a href = "./Table_of_Contents.html" >< img src = "./mpl_logo.jpg" alt = "[Home]" border = 0 align = "right" ></ a > Integral Constant</ h1 >< h3 > Description</ h3 >
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An Integral Constant is a class representing a value of a built-in integral type (< code > bool</ code > , < code > int</ code > , < code > long</ code > , etc.) in compile-time programs. An integral constant directly supports the increment/decrement operations within the range of the built-in integral type it wraps. Other arithmetic operations are supported through the external metafunctions.
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< h3 > Valid expressions</ h3 >
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< table border = "1" >
< tr >< th > Expression </ th >< th > Return type </ th ></ tr >
< tr >< td >< code > typename n::value_type</ code ></ td >< td > An < em > integral type</ em > </ td ></ tr >
< tr >< td >< code > typename n::type</ code ></ td >< td > A model of < a href = "./Integral_Constant.html" > Integral Constant</ a > </ td ></ tr >
< tr >< td >< code > n::value</ code ></ td >< td > A compile-time integral constant of < code > n::value_type</ code > </ td ></ tr >
< tr >< td >< code > typename n::next</ code ></ td >< td > A model of < a href = "./Integral_Constant.html" > Integral Constant</ a > </ td ></ tr >
< tr >< td >< code > typename n::prior</ code ></ td >< td > A model of < a href = "./Integral_Constant.html" > Integral Constant</ a > </ td ></ tr >
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< h3 > Expression semantics</ h3 >
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< table border = "1" >
< tr >< th > Expression </ th >< th > Complexity </ th >< th > Precondition </ th >< th > Semantics </ th >< th > Postcondition </ th ></ tr >
< tr >< td >< code > typename n::value_type</ code ></ td >< td > Amortized constant time</ td >< td ></ td >< td >< code > n::value_type</ code > is identical to < code > typeof(n::value)</ code ></ td >< td ></ td ></ tr >
< tr >< td >< code > typename n::type</ code ></ td >< td > Amortized constant time</ td >< td ></ td >< td > Self-reference.</ td >< td >< code > is_same< n::type,n> ::value == true</ code > </ td ></ tr >
< tr >< td >< code > n::value</ code ></ td >< td > Amortized constant time</ td >< td ></ td >< td > Value of < code > n</ code > .</ td >< td ></ td ></ tr >
< tr >< td >< code > typename n::next</ code ></ td >< td > Amortized constant time</ td >< td >< code > n::value_type</ code > supports an increment operation; < code > n::value</ code > is incrementable</ td >< td > Increment operation</ td >< td >< code > n::next::value == n::value + 1</ code > </ td ></ tr >
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< tr >< td >< code > typename n::prior</ code ></ td >< td > Amortized constant time</ td >< td >< code > n::value_type</ code > supports an decrement operation; < code > n::value</ code > is decrementable</ td >< td > Decrement operation</ td >< td >< code > n::prior::value == n::value - 1</ code > </ td ></ tr >
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</ table >
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< h3 > Models</ h3 >
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< ul >
< li >< code > integral_c</ code >
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< li >< code > int_</ code >
< li >< code > bool_</ code >
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</ ul >
< p >
< h3 > See also</ h3 >
< p >
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< code > next</ code > , < code > prior</ code >
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< p >< hr >
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< a href = "./Table_of_Contents.html" > Table of Contents</ a >< br > Last edited March 10, 2003 4:21 am</ body ></ html >
