substr: add interop with nullptr_t

biojppm · Sep 26, 2020 · 1ff3b64 · 1ff3b64
1 parent 4e17147
commit 1ff3b64
Show file tree

Hide file tree

Showing 2 changed files with 44 additions and 0 deletions.
diff --git a/src/c4/substr.hpp b/src/c4/substr.hpp
@@ -106,9 +106,11 @@ struct C4CORE_EXPORT basic_substring
 
     constexpr basic_substring(basic_substring const&) = default;
     constexpr basic_substring(basic_substring     &&) = default;
+    constexpr basic_substring(std::nullptr_t) : str(nullptr), len(0) {}
 
     basic_substring& operator= (basic_substring const&) = default;
     basic_substring& operator= (basic_substring     &&) = default;
+    basic_substring& operator= (std::nullptr_t) { str = nullptr; len = 0; return *this; }
 
 public:
 
@@ -223,6 +225,9 @@ struct C4CORE_EXPORT basic_substring
     bool operator<= (ro_substr const that) const { return this->compare(that) <= 0; }
     bool operator>= (ro_substr const that) const { return this->compare(that) >= 0; }
 
+    bool operator== (std::nullptr_t) const { return str == nullptr; }
+    bool operator!= (std::nullptr_t) const { return str != nullptr; }
+
 public:
 
     /** true if *this is a substring of that (ie, from the same buffer) */

diff --git a/test/substr.cpp b/test/substr.cpp
@@ -26,6 +26,45 @@ TEST(csubstr, ctor_from_char)
     EXPECT_EQ(s, "{foo: 2}");
 }
 
+TEST(csubstr, empty_vs_null)
+{
+    csubstr s;
+    EXPECT_TRUE(s.empty());
+    EXPECT_TRUE(s.len == 0);
+    EXPECT_TRUE(s.str == nullptr);
+    EXPECT_TRUE(s == nullptr);
+
+    s = "";
+    EXPECT_TRUE(s.empty());
+    EXPECT_TRUE(s.len == 0);
+    EXPECT_TRUE(s.str != nullptr);
+    EXPECT_TRUE(s != nullptr);
+
+    s = nullptr;
+    EXPECT_TRUE(s.empty());
+    EXPECT_TRUE(s.len == 0);
+    EXPECT_TRUE(s.str == nullptr);
+    EXPECT_TRUE(s == nullptr);
+
+    s = "";
+    EXPECT_TRUE(s.empty());
+    EXPECT_TRUE(s.len == 0);
+    EXPECT_TRUE(s.str != nullptr);
+    EXPECT_TRUE(s != nullptr);
+
+    s = {};
+    EXPECT_TRUE(s.empty());
+    EXPECT_TRUE(s.len == 0);
+    EXPECT_TRUE(s.str == nullptr);
+    EXPECT_TRUE(s == nullptr);
+
+    csubstr pp(nullptr);
+    EXPECT_TRUE(pp.empty());
+    EXPECT_TRUE(pp.len == 0);
+    EXPECT_TRUE(pp.str == nullptr);
+    EXPECT_TRUE(pp == nullptr);
+}
+
 TEST(substr, contains)
 {
     csubstr buf = "0123456789";