Type checking can be much simpler

zbench.zig

@@ -115,40 +115,8 @@ pub const Benchmark = struct {
             ),
         };
 
-        // Check the type of the benchmark parameter has a run function.
-        comptime switch (@typeInfo(T)) {
-            .Struct => |str| {
-                var run_found: bool = false;
-                for (str.decls) |decl| if (std.mem.eql(u8, decl.name, "run")) {
-                    run_found = true;
-                };
-                if (!run_found) @compileError(
-                    "benchmark must be a const ptr to a struct with a 'run' method",
-                );
-            },
-            else => @compileError(
-                "benchmark must be a const ptr to a struct with a 'run' method",
-            ),
-        };
-
-        // Check the run function has the proper type
-        comptime switch (@typeInfo(@TypeOf(@field(T, "run")))) {
-            .Fn => |info| {
-                if (info.params.len != 2) @compileError(
-                    "benchmark run function must have two parameters",
-                );
-                if (info.params[0].type != T) @compileError(
-                    "benchmark run function's first parameter must be self",
-                );
-                if (info.params[1].type != std.mem.Allocator) @compileError(
-                    "benchmark run function's second parameter must be an Allocator",
-                );
-                if (info.return_type != void) @compileError(
-                    "benchmark run function must return void",
-                );
-            },
-            else => unreachable,
-        };
+        // Check the benchmark parameter has a well typed run function.
+        _ = @as(fn (T, std.mem.Allocator) void, T.run);
 
         try self.benchmarks.append(self.allocator, Definition{
             .name = name,