Merge pull request RustPython#268 from mrecachinas/add-bool-doc

Add bool.__doc__ (addresses RustPython#260)

Author: windelbouwman

tests/snippets/bools.py

@@ -40,6 +40,8 @@ def __bool__(self):
 assert not (False and fake)
 assert (True and 5) == 5
 
+assert bool.__doc__ == "bool(x) -> bool\n\nReturns True when the argument x is true, False otherwise.\nThe builtins True and False are the only two instances of the class bool.\nThe class bool is a subclass of the class int, and cannot be subclassed."
+
 # Bools are also ints.
 assert isinstance(True, int)
 assert True + True == 2

vm/src/obj/objbool.rs

@@ -31,8 +31,15 @@ pub fn boolval(vm: &mut VirtualMachine, obj: PyObjectRef) -> Result<bool, PyObje
 
 pub fn init(context: &PyContext) {
     let ref bool_type = context.bool_type;
+    let bool_doc = "bool(x) -> bool
+
+Returns True when the argument x is true, False otherwise.
+The builtins True and False are the only two instances of the class bool.
+The class bool is a subclass of the class int, and cannot be subclassed.";
+
     context.set_attr(&bool_type, "__new__", context.new_rustfunc(bool_new));
     context.set_attr(&bool_type, "__repr__", context.new_rustfunc(bool_repr));
+    context.set_attr(&bool_type, "__doc__", context.new_str(bool_doc.to_string()));
 }
 
 pub fn not(vm: &mut VirtualMachine, obj: &PyObjectRef) -> PyResult {