[PATCH 1/2] libstdc++: Count pretty-printed tuple elements from 0 not 1

[Paul Smith via Gcc-patches]

Show 0-based offsets for std::tuple members, to match with std::get.

libstdc++-v3/ChangeLog:

* python/libstdcxx/v6/printers.py (StdTuplePrinter): don't increment
self.count until after generating the result string.
---
 libstdc++-v3/python/libstdcxx/v6/printers.py | 13 +++--
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/libstdc++-v3/python/libstdcxx/v6/printers.py 
b/libstdc++-v3/python/libstdcxx/v6/printers.py
index 550e0ecdd22..14a6d998690 100644
--- a/libstdc++-v3/python/libstdcxx/v6/printers.py
+++ b/libstdc++-v3/python/libstdcxx/v6/printers.py
@@ -560,16 +560,17 @@ class StdTuplePrinter:
 # Process left node and set it as head.
 self.head  = self.head.cast (nodes[0].type)

-self.count = self.count + 1
-
 # Finally, check the implementation.  If it is
 # wrapped in _M_head_impl return that, otherwise return
 # the value "as is".
 fields = impl.type.fields ()
-if len (fields) < 1 or fields[0].name != "_M_head_impl":
-return ('[%d]' % self.count, impl)
-else:
-return ('[%d]' % self.count, impl['_M_head_impl'])
+if len (fields) > 0 and fields[0].name == "_M_head_impl":
+impl = impl['_M_head_impl']
+
+out = '[%d]' % self.count
+self.count = self.count + 1
+
+return (out, impl)

 def __init__ (self, typename, val):
 self.typename = strip_versioned_namespace(typename)
--
2.28.0

[PATCH 2/2] libstdc++: Use template form for pretty-printing tuple elements

[Paul Smith via Gcc-patches]

std::tuple elements are retrieved via std::get<> (template) not
[] (array); have the generated output string match this.

libstdc++-v3/ChangeLog:

* python/libstdcxx/v6/printers.py (StdTuplePrinter): Use <> not [].
---
The previous patch seems uncontroversial to me.  I don't know about this one:
I'm not sure if there's any precedent for this type of output although to me
it looks better since tuples cannot be retrieved via array indexing.

 libstdc++-v3/python/libstdcxx/v6/printers.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libstdc++-v3/python/libstdcxx/v6/printers.py 
b/libstdc++-v3/python/libstdcxx/v6/printers.py
index 14a6d998690..0063a3185a6 100644
--- a/libstdc++-v3/python/libstdcxx/v6/printers.py
+++ b/libstdc++-v3/python/libstdcxx/v6/printers.py
@@ -567,7 +567,7 @@ class StdTuplePrinter:
 if len (fields) > 0 and fields[0].name == "_M_head_impl":
 impl = impl['_M_head_impl']

-out = '[%d]' % self.count
+out = '<%d>' % self.count
 self.count = self.count + 1

 return (out, impl)
--
2.28.0