Fix std::string_view support in transforming validators (#300)

* Fix std::string_view support in transforming validators * Fix single header * Fix formatting * Be more careful * fix string_view test
CLIUtils · Jul 25, 2019 · f0c0794 · f0c0794
1 parent 68c8b1b
commit f0c0794
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Showing 3 changed files with 28 additions and 1 deletion.
diff --git a/include/CLI/TypeTools.hpp b/include/CLI/TypeTools.hpp
@@ -10,6 +10,17 @@
 #include <type_traits>
 #include <vector>
 
+// [CLI11:verbatim]
+#if defined(CLI11_CPP17)
+#if defined(__has_include)
+#if __has_include(<string_view>)
+#include <string_view>
+#define CLI11_HAS_STRING_VIEW
+#endif
+#endif
+#endif
+// [CLI11:verbatim]
+
 namespace CLI {
 
 // Type tools
@@ -72,6 +83,10 @@ template <typename T> struct IsMemberType { using type = T; };
 /// The main custom type needed here is const char * should be a string.
 template <> struct IsMemberType<const char *> { using type = std::string; };
 
+#ifdef CLI11_HAS_STRING_VIEW
+template <> struct IsMemberType<std::string_view> { using type = std::string; };
+#endif
+
 namespace detail {
 
 // These are utilities for IsMember

diff --git a/include/CLI/Validators.hpp b/include/CLI/Validators.hpp
@@ -503,7 +503,7 @@ auto search(const T &set, const V &val, const std::function<V(V)> &filter_functi
     // if we haven't found it do the longer linear search with all the element translations
     auto &setref = detail::smart_deref(set);
     auto it = std::find_if(std::begin(setref), std::end(setref), [&](decltype(*std::begin(setref)) v) {
-        V a = detail::pair_adaptor<element_t>::first(v);
+        V a{detail::pair_adaptor<element_t>::first(v)};
         a = filter_function(a);
         return (a == val);
     });

diff --git a/tests/TransformTest.cpp b/tests/TransformTest.cpp
@@ -102,6 +102,18 @@ TEST_F(TApp, SimpleTransformFn) {
     EXPECT_EQ(value, 1);
 }
 
+#if defined(CLI11_HAS_STRING_VIEW)
+TEST_F(TApp, StringViewTransformFn) {
+    std::string value;
+    std::map<std::string_view, std::string_view> map = {// key length > std::string().capacity() [SSO length]
+                                                        {"a-rather-long-argument", "mapped"}};
+    app.add_option("-s", value)->transform(CLI::CheckedTransformer(map));
+    args = {"-s", "a-rather-long-argument"};
+    run();
+    EXPECT_EQ(value, "mapped");
+}
+#endif
+
 TEST_F(TApp, SimpleNumericalTransformFn) {
     int value;
     auto opt =