How to build %true = arith.constant true

Which type the true belong to? How to build it in Opbuilder as build interger?

OpBuilder builder(&(FuncBlock->back()));
    builder.create<arith::ConstantOp>(FuncBlock->back().getLoc(),builder.getI32Type(),builder.
    getZeroAttr(builder.getI32Type()));

I know there is getBoolAttr, but no getBoolType, what should I do?

Ok, just getI1Type()