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module strassens_matmul;
 
debug {
    static import std;
}
 
package {
    ulong getRowSize(T)(T[][] mat) {
        return mat[0].length;
    }
 
    ulong getColumnSize(T)(T[][] mat) {
        return mat.length;
    }
 
    T[][] createMatrix(T)(const ulong rowSize, const ulong columnSize) {
        return new T[][](rowSize, columnSize);
    }
 
    /// row and column are 0 index-based
    T* getPointPtr(T)(T[][] mat, const ulong row, const ulong column) {
        return &mat[row][column];
    }
 
    T getPointCopy(T)(T[][] mat, const ulong row, const ulong column) {
        return mat[row][column];
    }
 
    T[][] mulIterative(T)(scope const T[][] mat1, scope const T[][] mat2) {
        auto result = createMatrix!T(mat1.getRowSize, mat2.getColumnSize);
        foreach (row; 0 .. mat1.getRowSize()) {
            foreach (column; 0 .. mat2.getColumnSize()) {
                T value;
                foreach (i; 0 .. mat1.getRowSize()) {
                    value += mat1.getPointCopy(row, i) * mat2.getPointCopy(i, column);
                }
                *result.getPointPtr(row, column) = value;
            }
        }
        return result;
    }
}
 
void main() {
    const uint[][] matA = [[10, 20, 10], [4, 5, 6], [2, 3, 5]];
    const uint[][] matB = [[3, 2, 4], [3, 3, 9], [4, 4, 2]];
    const uint[][] matC = [[130, 120, 240], [51, 47, 73], [35, 33, 45]];
    assert(matA.mulIterative(matB) == matC);
}
 

prog.d:30:42: error: template strassens_matmul.getRowSize cannot deduce function from argument types !()(const(uint[][])), candidates are:
         auto result = createMatrix!T(mat1.getRowSize, mat2.getColumnSize);
                                          ^
prog.d:8:11: note: strassens_matmul.getRowSize(T)(T[][] mat)
     ulong getRowSize(T)(T[][] mat) {
           ^
prog.d:30:59: error: template strassens_matmul.getColumnSize cannot deduce function from argument types !()(const(uint[][])), candidates are:
         auto result = createMatrix!T(mat1.getRowSize, mat2.getColumnSize);
                                                           ^
prog.d:12:11: note: strassens_matmul.getColumnSize(T)(T[][] mat)
     ulong getColumnSize(T)(T[][] mat) {
           ^
prog.d:31:43: error: template strassens_matmul.getRowSize cannot deduce function from argument types !()(const(uint[][])), candidates are:
         foreach (row; 0 .. mat1.getRowSize()) {
                                           ^
prog.d:8:11: note: strassens_matmul.getRowSize(T)(T[][] mat)
     ulong getRowSize(T)(T[][] mat) {
           ^
prog.d:48:29: error: template instance strassens_matmul.mulIterative!uint error instantiating
     assert(matA.mulIterative(matB) == matC);
                             ^
prog.d:48:29: error: function strassens_matmul.mulIterative!uint.mulIterative is not accessible from module strassens_matmul
     assert(matA.mulIterative(matB) == matC);
                             ^

Standard output is empty