cxx: Correct dict interface

Package cxx was added in 9785f2d3 (cxx: New package), but the interface
that cxx:dict provided turned out to be not optimal:

    dict.get  was returning (v, ok), and
    dict.pop  ----//---

Correct dict.get and dict.pop to return just value, and, similarly to
channels API, provide additional dict.get_ and dict.pop_ - extended
versions that also return ok:

    dict.get(k)  -> v
    dict.pop(k)  -> v
    dict.get_(k) -> (v, ok)
    dict.pop_(k) -> (v, ok)

This time add tests.

golang/.gitignore

 /_context.cpp
+/_cxx_test.cpp
 /_errors_test.cpp
 /_fmt_test.cpp
 /_golang.cpp

golang/_cxx_test.pyx

+# -*- coding: utf-8 -*-
+# cython: language_level=2
+# distutils: language=c++
+#
+# Copyright (C) 2020  Nexedi SA and Contributors.
+#                     Kirill Smelkov <kirr@nexedi.com>
+#
+# This program is free software: you can Use, Study, Modify and Redistribute
+# it under the terms of the GNU General Public License version 3, or (at your
+# option) any later version, as published by the Free Software Foundation.
+#
+# You can also Link and Combine this program with other software covered by
+# the terms of any of the Free Software licenses or any of the Open Source
+# Initiative approved licenses and Convey the resulting work. Corresponding
+# source of such a combination shall include the source code for all other
+# software used.
+#
+# This program is distributed WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+#
+# See COPYING file for full licensing terms.
+# See https://www.nexedi.com/licensing for rationale and options.
+
+from __future__ import print_function, absolute_import
+
+from golang cimport topyexc
+
+
+# cxx_test.cpp
+cdef extern from * nogil:
+    """
+    extern void _test_cxx_dict();
+    extern void _test_cxx_set();
+    """
+    void _test_cxx_dict()                       except +topyexc
+    void _test_cxx_set()                        except +topyexc
+def test_cxx_dict():
+    with nogil:
+        _test_cxx_dict()
+def test_cxx_set():
+    with nogil:
+        _test_cxx_set()

golang/cxx.h

 #ifndef _NXD_LIBGOLANG_CXX_H
 #define _NXD_LIBGOLANG_CXX_H
 
-// Copyright (C) 2019  Nexedi SA and Contributors.
-//                     Kirill Smelkov <kirr@nexedi.com>
+// Copyright (C) 2019-2020  Nexedi SA and Contributors.
+//                          Kirill Smelkov <kirr@nexedi.com>
 //
 // This program is free software: you can Use, Study, Modify and Redistribute
 // it under the terms of the GNU General Public License version 3, or (at your
@@ -31,6 +31,8 @@ namespace golang {
 namespace cxx {
 
 using std::tuple;
+using std::tie;
+using std::make_tuple;
 
 // dict wraps unordered_map into ergonomic interface.
 template<typename Key, typename Value>
@@ -41,8 +43,14 @@ struct dict : std::unordered_map<Key, Value> {
         return d.find(k) != d.end();
     }
 
-    // get implements `d[k] -> (v, ok)`.
-    tuple<Value, bool> get(const Key &k) const {
+    // get implements `d[k] -> v`.
+    Value get(const Key &k) const {
+        Value v; bool _; tie(v, _) = get_(k);
+        return v;
+    }
+
+    // get_ implements `d[k] -> (v, ok)`.
+    tuple<Value, bool> get_(const Key &k) const {
         const dict &d = *this;
         auto _ = d.find(k);
         if (_ == d.end())
@@ -50,8 +58,14 @@ struct dict : std::unordered_map<Key, Value> {
         return make_tuple(_->second, true);
     }
 
-    // pop implements `d[k] -> (v, ok); del d[k]`.
-    tuple<Value, bool> pop(const Key &k) {
+    // pop implements `d[k] -> v; del d[k]`.
+    Value pop(const Key &k) {
+        Value v; bool _; tie(v, _) = pop_(k);
+        return v;
+    }
+
+    // pop_ implements `d[k] -> (v, ok); del d[k]`.
+    tuple<Value, bool> pop_(const Key &k) {
         dict &d = *this;
         auto _ = d.find(k);
         if (_ == d.end())

golang/cxx.pxd

 # cython: language_level=2
-# Copyright (C) 2019  Nexedi SA and Contributors.
-#                     Kirill Smelkov <kirr@nexedi.com>
+# Copyright (C) 2019-2020  Nexedi SA and Contributors.
+#                          Kirill Smelkov <kirr@nexedi.com>
 #
 # This program is free software: you can Use, Study, Modify and Redistribute
 # it under the terms of the GNU General Public License version 3, or (at your
@@ -25,8 +25,8 @@ cimport libcpp.unordered_set
 cdef extern from "<golang/cxx.h>" namespace "golang::cxx" nogil:
     cppclass dict[Key, Value] (libcpp.unordered_map.unordered_map[Key, Value]):
         bint has(Key k) const
-        # TODO get
-        # TODO pop
+        # TODO get/get_
+        # TODO pop/pop_
 
     cppclass set[Key] (libcpp.unordered_set.unordered_set[Key]):
         bint has(Key k) const

golang/cxx_test.cpp

+// Copyright (C) 2020  Nexedi SA and Contributors.
+//                     Kirill Smelkov <kirr@nexedi.com>
+//
+// This program is free software: you can Use, Study, Modify and Redistribute
+// it under the terms of the GNU General Public License version 3, or (at your
+// option) any later version, as published by the Free Software Foundation.
+//
+// You can also Link and Combine this program with other software covered by
+// the terms of any of the Free Software licenses or any of the Open Source
+// Initiative approved licenses and Convey the resulting work. Corresponding
+// source of such a combination shall include the source code for all other
+// software used.
+//
+// This program is distributed WITHOUT ANY WARRANTY; without even the implied
+// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+//
+// See COPYING file for full licensing terms.
+// See https://www.nexedi.com/licensing for rationale and options.
+
+#include "golang/cxx.h"
+#include "golang/_testing.h"
+using namespace golang;
+using std::tie;
+
+void _test_cxx_dict() {
+    cxx::dict<string, int> d;
+    d["abc"] = 1;
+    d["def"] = 2;
+
+    // has
+    ASSERT(d.has("abc"));
+    ASSERT(d.has("def"));
+    ASSERT(!d.has("zzz"));
+
+    // get
+    ASSERT_EQ(d.get("abc"), 1);
+    ASSERT_EQ(d.get("def"), 2);
+    ASSERT_EQ(d.get("zzz"), 0);
+
+    int v; bool ok;
+
+    // get_
+    tie(v, ok) = d.get_("abc");
+    ASSERT_EQ(v, 1); ASSERT_EQ(ok, true);
+
+    tie(v, ok) = d.get_("def");
+    ASSERT_EQ(v, 2); ASSERT_EQ(ok, true);
+
+    tie(v, ok) = d.get_("zzz");
+    ASSERT_EQ(v, 0); ASSERT_EQ(ok, false);
+
+    // pop / pop_
+    ASSERT_EQ(d.pop("zzz"), 0);
+    tie(v, ok) = d.pop_("zzz");
+    ASSERT_EQ(v, 0); ASSERT_EQ(ok, false);
+
+    ASSERT(d.has("def"));
+    ASSERT_EQ(d.pop("def"), 2);
+    ASSERT(!d.has("def"));
+    ASSERT_EQ(d.pop("def"), 0);
+    ASSERT(!d.has("def"));
+
+    ASSERT(d.has("abc"));
+    tie(v, ok) = d.pop_("abc");
+    ASSERT_EQ(v, 1); ASSERT_EQ(ok, true);
+    ASSERT(!d.has("abc"));
+    tie(v, ok) = d.pop_("abc");
+    ASSERT_EQ(v, 0); ASSERT_EQ(ok, false);
+}
+
+void _test_cxx_set() {
+    cxx::set<string> s;
+    s.insert("abc");
+    s.insert("def");
+
+    // has
+    ASSERT(s.has("abc"));
+    ASSERT(s.has("def"));
+    ASSERT(!s.has("zzz"));
+
+    // has after erase
+    s.erase("zzz");
+    ASSERT(s.has("abc"));
+    ASSERT(s.has("def"));
+    ASSERT(!s.has("zzz"));
+
+    s.erase("def");
+    ASSERT(s.has("abc"));
+    ASSERT(!s.has("def"));
+    ASSERT(!s.has("zzz"));
+
+    s.erase("abc");
+    ASSERT(!s.has("abc"));
+    ASSERT(!s.has("def"));
+    ASSERT(!s.has("zzz"));
+}

golang/cxx_test.py

+# -*- coding: utf-8 -*-
+# Copyright (C) 2020  Nexedi SA and Contributors.
+#                     Kirill Smelkov <kirr@nexedi.com>
+#
+# This program is free software: you can Use, Study, Modify and Redistribute
+# it under the terms of the GNU General Public License version 3, or (at your
+# option) any later version, as published by the Free Software Foundation.
+#
+# You can also Link and Combine this program with other software covered by
+# the terms of any of the Free Software licenses or any of the Open Source
+# Initiative approved licenses and Convey the resulting work. Corresponding
+# source of such a combination shall include the source code for all other
+# software used.
+#
+# This program is distributed WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+#
+# See COPYING file for full licensing terms.
+# See https://www.nexedi.com/licensing for rationale and options.
+
+from __future__ import print_function, absolute_import
+
+from golang.golang_test import import_pyx_tests
+
+import_pyx_tests("golang._cxx_test")

setup.py

@@ -251,6 +251,10 @@ setup(
                     Ext('golang._context',
                         ['golang/_context.pyx']),
 
+                    Ext('golang._cxx_test',
+                        ['golang/_cxx_test.pyx',
+                         'golang/cxx_test.cpp']),
+
                     Ext('golang._errors_test',
                         ['golang/_errors_test.pyx',
                          'golang/errors_test.cpp']),