Change in default behaviour wrapping C++ bool for Python.

Only a Python True or False will now work for C++ bool parameters.
This fixes overloading bool with other types.

CHANGES.current

@@ -5,6 +5,62 @@ See the RELEASENOTES file for a summary of changes in each release.
 Version 3.0.0 (in progress)
 ============================
 
+2014-03-06: wsfulton
+            [Python] Change in default behaviour wrapping C++ bool. Only a Python True or False
+            will now work for C++ bool parameters. This fixes overloading bool with other types.
+            Python 2.3 minimum is now required for wrapping bool.
+
+            When wrapping:
+
+              const char* overloaded(bool value) { return "bool"; }
+              const char* overloaded(int value) { return "int"; }
+
+            Previous behaviour:
+              >>> overloaded(False)
+              'int'
+              >>> overloaded(True)
+              'int'
+              >>> overloaded(0)
+              'int'
+
+            Now we get the expected behaviour:
+              >>> overloaded(False)
+              'bool'
+              >>> overloaded(0)
+              'int'
+
+            The consequence is when wrapping bool in non-overloaded functions:
+
+              const char* boolfunction(bool value) { return value ? "true" : "false"; }
+
+            The previous behaviour was very Pythonic:
+              >>> boolfunction("")
+              'false'
+              >>> boolfunction("hi")
+              'true'
+              >>> boolfunction(12.34)
+              'true'
+              >>> boolfunction(0)
+              'false'
+              >>> boolfunction(1)
+              'true'
+
+            Now the new behaviour more along the lines of C++ due to stricter type checking. The
+            above calls result in an exception and need to be explicitly converted into a bool as
+            follows:
+              >>> boolfunction(0)
+              Traceback (most recent call last):
+                File "<stdin>", line 1, in <module>
+              TypeError: in method 'boolfunction', argument 1 of type 'bool'
+              >>> boolfunction(bool(0))
+              'false'
+
+            The old behaviour can be resurrected by passing the -DSWIG_PYTHON_LEGACY_BOOL command line
+            parameter when executing SWIG. Typemaps can of course be written to customise the behaviour
+            for specific parameters.
+
+            *** POTENTIAL INCOMPATIBILITY  ***
+
 2014-03-06: wsfulton
 	    Fix SF Bug #1363 - Problem with method overloading when some methods are added by %extend
             and others are real methods and using template default parameters with smart pointers.

Examples/test-suite/common.mk

@@ -294,6 +294,7 @@ CPP_TEST_CASES += \
 	operator_pointer_ref \
 	operbool \
 	ordering \
+	overload_bool \
 	overload_copy \
 	overload_extend \
 	overload_method \

Examples/test-suite/overload_bool.i

@@ -0,0 +1,19 @@
+%module overload_bool
+
+%inline %{
+const char* overloaded(bool value) { return "bool"; }
+const char* overloaded(int value) { return "int"; }
+const char* overloaded(const char *value) { return "string"; }
+
+const char* boolfunction(bool value) { return value ? "true" : "false"; }
+const char* intfunction(int value) { return "int"; }
+
+
+// Const references
+const char* overloaded_ref(bool const& value) { return "bool"; }
+const char* overloaded_ref(int const& value) { return "int"; }
+const char* overloaded_ref(const char *value) { return "string"; }
+
+const char* boolfunction_ref(bool const& value) { return value ? "true" : "false"; }
+const char* intfunction_ref(int const& value) { return "int"; }
+%}

Examples/test-suite/python/li_std_vector_extra_runme.py

@@ -17,10 +17,10 @@ halve_in_place(dv)
 
 
 bv = BoolVector(4)
-bv[0]= 1
-bv[1]= 0
-bv[2]= 4
-bv[3]= 0
+bv[0]= bool(1)
+bv[1]= bool(0)
+bv[2]= bool(4)
+bv[3]= bool(0)
 
 if bv[0] != bv[2]:
     raise RuntimeError,"bad std::vector<bool> mapping"

Examples/test-suite/python/overload_bool_runme.py

@@ -0,0 +1,55 @@
+import overload_bool
+
+# Overloading bool, int, string
+if overload_bool.overloaded(True) != "bool":
+  raise RuntimeError("wrong!")
+if overload_bool.overloaded(False) != "bool":
+  raise RuntimeError("wrong!")
+
+if overload_bool.overloaded(0) != "int":
+  raise RuntimeError("wrong!")
+if overload_bool.overloaded(1) != "int":
+  raise RuntimeError("wrong!")
+if overload_bool.overloaded(2) != "int":
+  raise RuntimeError("wrong!")
+
+if overload_bool.overloaded("1234") != "string":
+  raise RuntimeError("wrong!")
+
+# Test bool masquerading as int
+if overload_bool.intfunction(True) != "int":
+  raise RuntimeError("wrong!")
+if overload_bool.intfunction(False) != "int":
+  raise RuntimeError("wrong!")
+
+# Test int masquerading as bool
+# Not possible
+
+
+#############################################
+
+# Overloading bool, int, string
+if overload_bool.overloaded_ref(True) != "bool":
+  raise RuntimeError("wrong!")
+if overload_bool.overloaded_ref(False) != "bool":
+  raise RuntimeError("wrong!")
+
+if overload_bool.overloaded_ref(0) != "int":
+  raise RuntimeError("wrong!")
+if overload_bool.overloaded_ref(1) != "int":
+  raise RuntimeError("wrong!")
+if overload_bool.overloaded_ref(2) != "int":
+  raise RuntimeError("wrong!")
+
+if overload_bool.overloaded_ref("1234") != "string":
+  raise RuntimeError("wrong!")
+
+# Test bool masquerading as int
+if overload_bool.intfunction_ref(True) != "int":
+  raise RuntimeError("wrong!")
+if overload_bool.intfunction_ref(False) != "int":
+  raise RuntimeError("wrong!")
+
+# Test int masquerading as bool
+# Not possible
+

Examples/test-suite/python/primitive_ref_runme.py

@@ -30,7 +30,7 @@ if ref_float(3.5) != 3.5:
 if ref_double(3.5) != 3.5:
     raise RuntimeError
 
-if ref_bool(1) != 1:
+if ref_bool(True) != True:
     raise RuntimeError
 
 if ref_char('x') != 'x':

Examples/test-suite/python/reference_global_vars_runme.py

@@ -5,12 +5,12 @@ if getconstTC().num != 33:
     raise RuntimeError
 
 # primitive reference variables
-cvar.var_bool = createref_bool(0)
-if value_bool(cvar.var_bool) != 0:
+cvar.var_bool = createref_bool(False)
+if value_bool(cvar.var_bool) != False:
     raise RuntimeError
 
-cvar.var_bool = createref_bool(1)
-if value_bool(cvar.var_bool) != 1:
+cvar.var_bool = createref_bool(True)
+if value_bool(cvar.var_bool) != True:
     raise RuntimeError
 
 cvar.var_char = createref_char('w')

Examples/test-suite/python/std_containers_runme.py

@@ -46,7 +46,7 @@ for i in range(0,len(m)):
     if m[i][j] != im[i][j]:
       raise RuntimeError, "bad getslice"
 
-m = ((1,0,1),(1,1),(1,1))
+m = ((True,False,True),(True,True),(True,True))
 im = std_containers.midentb(m)
 for i in range(0,len(m)):
   for j in range(0,len(m[i])):

Examples/test-suite/ruby/overload_bool_runme.rb

@@ -0,0 +1,88 @@
+#!/usr/bin/env ruby
+#
+# Put description here
+#
+# 
+# 
+# 
+#
+
+require 'swig_assert'
+
+require 'overload_bool'
+
+include Overload_bool
+
+# Overloading bool, int, string
+if overloaded(true) != "bool"
+  raise RuntimeError, "wrong!"
+end
+if overloaded(false) != "bool"
+  raise RuntimeError, "wrong!"
+end
+
+if overloaded(0) != "int"
+  raise RuntimeError, "wrong!"
+end
+if overloaded(1) != "int"
+  raise RuntimeError, "wrong!"
+end
+if overloaded(2) != "int"
+  raise RuntimeError, "wrong!"
+end
+
+if overloaded("1234") != "string"
+  raise RuntimeError, "wrong!"
+end
+
+# Test bool masquerading as integer
+# Not possible
+
+# Test int masquerading as bool
+if boolfunction(0) != "false"
+  raise RuntimeError, "wrong!"
+end
+if boolfunction(1) != "true"
+  raise RuntimeError, "wrong!"
+end
+if boolfunction(2) != "true"
+  raise RuntimeError, "wrong!"
+end
+
+#############################################
+
+# Overloading bool, int, string
+if overloaded_ref(true) != "bool"
+  raise RuntimeError, "wrong!"
+end
+if overloaded_ref(false) != "bool"
+  raise RuntimeError, "wrong!"
+end
+
+if overloaded_ref(0) != "int"
+  raise RuntimeError, "wrong!"
+end
+if overloaded_ref(1) != "int"
+  raise RuntimeError, "wrong!"
+end
+if overloaded_ref(2) != "int"
+  raise RuntimeError, "wrong!"
+end
+
+if overloaded_ref("1234") != "string"
+  raise RuntimeError, "wrong!"
+end
+
+# Test bool masquerading as integer
+# Not possible
+
+# Test int masquerading as bool
+if boolfunction_ref(0) != "false"
+  raise RuntimeError, "wrong!"
+end
+if boolfunction_ref(1) != "true"
+  raise RuntimeError, "wrong!"
+end
+if boolfunction_ref(2) != "true"
+  raise RuntimeError, "wrong!"
+end

Lib/python/pyprimtypes.swg

@@ -12,6 +12,8 @@ SWIGINTERNINLINE PyObject*
 }
 }
 
+#ifdef SWIG_PYTHON_LEGACY_BOOL
+// Default prior to SWIG 3.0.0
 %fragment(SWIG_AsVal_frag(bool),"header",
 	  fragment=SWIG_AsVal_frag(long)) {
 SWIGINTERN int
@@ -24,6 +26,23 @@ SWIG_AsVal_dec(bool)(PyObject *obj, bool *val)
   return SWIG_OK;
 }
 }
+#else
+%fragment(SWIG_AsVal_frag(bool),"header",
+	  fragment=SWIG_AsVal_frag(long)) {
+SWIGINTERN int
+SWIG_AsVal_dec(bool)(PyObject *obj, bool *val)
+{
+  int r;
+  if (!PyBool_Check(obj))
+    return SWIG_ERROR;
+  r = PyObject_IsTrue(obj);
+  if (r == -1)
+    return SWIG_ERROR;
+  if (val) *val = r ? true : false;
+  return SWIG_OK;
+}
+}
+#endif
 
 /* int */
 

Lib/python/pytypemaps.swg

@@ -5,9 +5,11 @@
 /* ------------------------------------------------------------
  *  Fragment section
  * ------------------------------------------------------------ */
-/* bool is dangerous in Python, change precedence */
+#ifdef SWIG_PYTHON_LEGACY_BOOL
+// Default prior to SWIG 3.0.0
 #undef SWIG_TYPECHECK_BOOL
 %define SWIG_TYPECHECK_BOOL             10000 %enddef
+#endif
 
 /* Include fundamental fragment definitions */
 %include <typemaps/fragments.swg>