return integer type with same precision

Author: simeonschaub

base/special/trig.jl

@@ -860,8 +860,10 @@ function cospi(x::T) where T<:Union{Integer,Rational}
     end
 end
 
-sinpi(x::Integer) = 0
-cospi(x::Integer) = isodd(x) ? -1 : 1
+sinpi(x::T) where {T<:Integer} = zero(signed(T))
+sinpi(x::Bool) = 0
+cospi(x::T) where {T<:Integer} = isodd(x) ? one(signed(T)) : -one(signed(T))
+cospi(x::Bool) = x ? -1 : 1
 sinpi(x::Real) = sinpi(float(x))
 cospi(x::Real) = cospi(float(x))