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tanmaykm/safe.jl

Created March 17, 2015 13:49
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safe (no overflow) methods
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safe.jl
safe_add{T<:Integer}(n1::T, n2::T) = ((n2 > 0) ? (n1 > (typemax(T) - n2)) : (n1 < (typemin(T) - n2))) ? Nullable{T}() : Nullable{T}(n1 + n2)
safe_mul{T<:Integer}(n1::T, n2::T) = ((n2 > 0) ? ((n1 > div(typemax(T),n2)) || (n1 < div(typemin(T),n2))) :
(n2 < -1) ? ((n1 > div(typemin(T),n2)) || (n1 < div(typemax(T),n2))) :
((n2 == -1) && n1 == typemin(T))) ? Nullable{T}() : Nullable{T}(n1 * n2)
#safe_sub{T<:Integer}(n1::T, n2::T) = ((n2 > 0) ? (n1 < (typemin(T) + n2)) : (n1 > (typemax(T) + n2))) ? Nullable{T}() : Nullable{T}(n1 - n2)
#safe_div{T<:Integer}(n1::T, n2::T) = ((n1 == typemin(T)) && (n2 == T(-1))) ? Nullable{T}() : Nullable{T}(div(n1, n2))
#safe_abs{T<:Integer}(n::T) = (n == typemin(T)) ? Nullable{T}() : abs(n)
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