Simple ADL example.

HappyCerberus · HappyCerberus · commit 98f84e98fc2e · 2022-09-20T15:29:11.000+02:00
diff --git a/code_examples/theory/CMakeLists.txt b/code_examples/theory/CMakeLists.txt
@@ -15,3 +15,6 @@ install(TARGETS initializer_list DESTINATION bin)
 
 add_executable(adl_unqalified adl_unqalified.cpp)
 # Compile only
+
+add_executable(adl_simple adl_simple.cpp)
+# Compile only
diff --git a/code_examples/theory/adl_code.h b/code_examples/theory/adl_code.h
@@ -10,5 +10,5 @@ std::ostream& operator << (std::ostream& s, const X&) {
 void calling_site() {
 	Custom::X x;
 	Custom::operator << (std::cout, x); // OK, explicit call
-	std::cout << x; // OK, unqualified operator <<, ADL
+	std::cout << x; // Requires ADL
 }
diff --git a/code_examples/theory/adl_simple.cpp b/code_examples/theory/adl_simple.cpp
@@ -0,0 +1,5 @@
+#include <iostream>
+#include "adl_simple_code.h"
+int main() {
+    calling_site();
+}
diff --git a/code_examples/theory/adl_simple_code.h b/code_examples/theory/adl_simple_code.h
@@ -0,0 +1,17 @@
+namespace A {
+    struct X {};
+    void some_func(const X&) {}
+}
+
+namespace B {
+    struct Y {};
+    void some_func(const Y&) {}
+}
+
+void some_func(const auto&) {}
+
+void calling_site() {
+    A::X x; B::Y y;
+    some_func(x); // Calls A::some_func     
+    some_func(y); // Calls B::some_func
+}
diff --git a/code_examples/theory/adl_unqalified.cpp b/code_examples/theory/adl_unqalified.cpp
@@ -1,2 +1,4 @@
 #include "adl_unqalified_code.h"
-int main() {}
+int main() {
+	A::B::calling_site();
+}
diff --git a/code_examples/theory/adl_unqalified_code.h b/code_examples/theory/adl_unqalified_code.h
@@ -1,11 +1,13 @@
 namespace A {
 void some_call(int) {}
+void some_call(const char*) {}
 namespace B {
 void some_call(double) {}
 
-void test() {
+void calling_site() {
     some_call(1);   // A::B::some_call
     some_call(2.0); // A::B::some_call
+    //some_call("hello world"); Will not compile, no conversion from const char* -> double
 }
 }
 }

Original file line number	Diff line number	Diff line change
`@@ -10,5 +10,5 @@ std::ostream& operator << (std::ostream& s, const X&) {`
`10`	`10`	`void calling_site() {`
`11`	`11`	`Custom::X x;`
`12`	`12`	`Custom::operator << (std::cout, x); // OK, explicit call`
`13`		`- std::cout << x; // OK, unqualified operator <<, ADL`
	`13`	`+ std::cout << x; // Requires ADL`
`14`	`14`	`}`
Original file line number	Diff line number	Diff line change
`@@ -1,11 +1,13 @@`
`1`	`1`	`namespace A {`
`2`	`2`	`void some_call(int) {}`
	`3`	`+void some_call(const char*) {}`
`3`	`4`	`namespace B {`
`4`	`5`	`void some_call(double) {}`
`5`	`6`
`6`		`-void test() {`
	`7`	`+void calling_site() {`
`7`	`8`	`some_call(1); // A::B::some_call`
`8`	`9`	`some_call(2.0); // A::B::some_call`
	`10`	`+ //some_call("hello world"); Will not compile, no conversion from const char* -> double`
`9`	`11`	`}`
`10`	`12`	`}`
`11`	`13`	`}`