module BlackBoxInverter(
    input  [0:0] in,
    output [0:0] out
);
  assign out = !in;
endmodule

module BlackBoxPassthrough(
    input  [0:0] in,
    output [0:0] out
);
  assign out = in;
endmodule

module BlackBoxPassthrough2(
    input  [0:0] in,
    output [0:0] out
);
  assign out = in;
endmodule

module BlackBoxMinus(
    input  [15:0] in1,
    input  [15:0] in2,
    output [15:0] out
);
  assign out = in1 + in2;
endmodule

module BlackBoxRegister(
    input  [0:0] clock,
    input  [0:0] in,
    output [0:0] out
);
  reg [0:0] register;
  always @(posedge clock) begin
    register <= in;
  end
  assign out = register;
endmodule

module BlackBoxConstant #(
  parameter int WIDTH=1,
  parameter int VALUE=1
) (
  output [WIDTH-1:0] out
);
  assign out = VALUE;
endmodule

module BlackBoxStringParam #(
  parameter string STRING = "zero"
) (
  output [31:0] out
);
  assign out = (STRING == "one" )? 1 :
               (STRING == "two" )? 2 : 0;
endmodule

module BlackBoxRealParam #(
  parameter real REAL = 0.0
) (
  output [63:0] out
);
  assign out = $realtobits(REAL);
endmodule

module BlackBoxTypeParam #(
  parameter type T = bit
) (
  output T out
);
  assign out = 32'hdeadbeef;
endmodule