On 16.04.2011 12:12, simendsjo wrote:
int[3] a = [1,2,4];
float[3] b = [1,2,4];
float[3] c;
// Why doesn't this work?
c = a[] + b[]; // Error: incompatible types for ((a[]) + (b[])): 'int[]'
and 'float[]'
// When this works?
c[0] = a[0] + b[0];
c[1] = a[1] + b[1];
c[2] = a[2] + b[2];
assert(c == [2,4,8]);
I tried using a template mixin to avoid having to type this all over,
but I cannot get it to work.. I think I have something wrong with my
alias usage, but that's just speculating :)
mixin template ArrayVectorOp(string op, alias dest, alias a, alias b, int I)
if(dest.length == a.length && dest.length == b.length && I >= 1 && I <=
dest.length) {
// dest[I-1] = a[I-1] op b[I-1]
mixin(dest.stringof~"["~(I-1).stringof~"]"
" = "
~a.stringof~"["~(I-1).stringof~"]"
~op
~b.stringof~"["~(I-1).stringof~"];");
static if(I > 1)
mixin ArrayVectorOp!(op, dest, a, b, I-1);
}
void main() {
int[3] a = [1, 2, 3];
float[3] b = [2.1, 3.2, 4.3];
float[3] c;
mixin ArrayVectorOp!("+", c, a, b, a.length);
assert(c == [3.1, 5.2, 7.3]);
}
Gives the following output:
t.d(4): no identifier for declarator c[3 - 1]
t.d(4): Error: c is used as a type
t.d(4): Error: cannot implicitly convert expression (cast(float)a[2u] +
b[2u]) o
f type float to const(_error_[])
t.d(4): no identifier for declarator c[2 - 1]
t.d(4): Error: c is used as a type
t.d(4): Error: cannot implicitly convert expression (cast(float)a[1u] +
b[1u]) o
f type float to const(_error_[])
t.d(4): no identifier for declarator c[1 - 1]
t.d(4): Error: c is used as a type
t.d(4): Error: cannot implicitly convert expression (cast(float)a[0u] +
b[0u]) o
f type float to const(_error_[])
t.d(11): Error: mixin
t.main.ArrayVectorOp!("+",c,a,b,3u).ArrayVectorOp!(op,c,a,
b,2).ArrayVectorOp!(op,c,a,b,1) error instantiating
t.d(11): Error: mixin
t.main.ArrayVectorOp!("+",c,a,b,3u).ArrayVectorOp!(op,c,a,
b,2) error instantiating
t.d(18): Error: mixin t.main.ArrayVectorOp!("+",c,a,b,3u) error
instantiating
