diff --git a/Rx/v2/examples/doxygen/amb.cpp b/Rx/v2/examples/doxygen/amb.cpp
index e7dfaa6fc..eab7f7ef5 100644
--- a/Rx/v2/examples/doxygen/amb.cpp
+++ b/Rx/v2/examples/doxygen/amb.cpp
@@ -30,7 +30,7 @@ SCENARIO("implicit amb sample"){
     printf("//! [implicit amb sample]\n");
 }
 
-std::string get_pid();
+#include "main.hpp"
 
 SCENARIO("threaded amb sample"){
     printf("//! [threaded amb sample]\n");
diff --git a/Rx/v2/examples/doxygen/buffer.cpp b/Rx/v2/examples/doxygen/buffer.cpp
index 58f023a6c..503db126a 100644
--- a/Rx/v2/examples/doxygen/buffer.cpp
+++ b/Rx/v2/examples/doxygen/buffer.cpp
@@ -35,7 +35,7 @@ SCENARIO("buffer count+skip sample"){
     printf("//! [buffer count+skip sample]\n");
 }
 
-std::string get_pid();
+#include "main.hpp"
 
 SCENARIO("buffer period+skip+coordination sample"){
     printf("//! [buffer period+skip+coordination sample]\n");
diff --git a/Rx/v2/examples/doxygen/combine_latest.cpp b/Rx/v2/examples/doxygen/combine_latest.cpp
index b220da48e..5f2168be0 100644
--- a/Rx/v2/examples/doxygen/combine_latest.cpp
+++ b/Rx/v2/examples/doxygen/combine_latest.cpp
@@ -17,7 +17,7 @@ SCENARIO("combine_latest sample"){
     printf("//! [combine_latest sample]\n");
 }
 
-std::string get_pid();
+#include "main.hpp"
 
 SCENARIO("Coordination combine_latest sample"){
     printf("//! [Coordination combine_latest sample]\n");
diff --git a/Rx/v2/examples/doxygen/concat_map.cpp b/Rx/v2/examples/doxygen/concat_map.cpp
index 957665f56..a087431eb 100644
--- a/Rx/v2/examples/doxygen/concat_map.cpp
+++ b/Rx/v2/examples/doxygen/concat_map.cpp
@@ -22,7 +22,7 @@ SCENARIO("concat_map sample"){
     printf("//! [concat_map sample]\n");
 }
 
-std::string get_pid();
+#include "main.hpp"
 
 SCENARIO("threaded concat_map sample"){
     printf("//! [threaded concat_map sample]\n");
diff --git a/Rx/v2/examples/doxygen/flat_map.cpp b/Rx/v2/examples/doxygen/flat_map.cpp
index 0c88cbe83..3e0a09f76 100644
--- a/Rx/v2/examples/doxygen/flat_map.cpp
+++ b/Rx/v2/examples/doxygen/flat_map.cpp
@@ -22,7 +22,7 @@ SCENARIO("flat_map sample"){
     printf("//! [flat_map sample]\n");
 }
 
-std::string get_pid();
+#include "main.hpp"
 
 SCENARIO("threaded flat_map sample"){
     printf("//! [threaded flat_map sample]\n");
diff --git a/Rx/v2/examples/doxygen/from.cpp b/Rx/v2/examples/doxygen/from.cpp
index 15186ba42..7cc22768e 100644
--- a/Rx/v2/examples/doxygen/from.cpp
+++ b/Rx/v2/examples/doxygen/from.cpp
@@ -13,7 +13,7 @@ SCENARIO("from sample"){
     printf("//! [from sample]\n");
 }
 
-std::string get_pid();
+#include "main.hpp"
 
 SCENARIO("threaded from sample"){
     printf("//! [threaded from sample]\n");
diff --git a/Rx/v2/examples/doxygen/group_by.cpp b/Rx/v2/examples/doxygen/group_by.cpp
index d30f33448..b716d6fce 100644
--- a/Rx/v2/examples/doxygen/group_by.cpp
+++ b/Rx/v2/examples/doxygen/group_by.cpp
@@ -23,7 +23,7 @@ SCENARIO("group_by sample"){
 }
 
 //! [group_by full intro]
-bool less(int v1, int v2){
+static bool less(int v1, int v2){
     return v1 < v2;
 }
 //! [group_by full intro]
diff --git a/Rx/v2/examples/doxygen/main.cpp b/Rx/v2/examples/doxygen/main.cpp
index 8a831f2eb..4da59c5a7 100644
--- a/Rx/v2/examples/doxygen/main.cpp
+++ b/Rx/v2/examples/doxygen/main.cpp
@@ -4,6 +4,9 @@
 #include <iostream>
 #include <thread>
 #include <string>
+
+#include "main.hpp"
+
 std::string get_pid() {
     std::stringstream s;
     s << std::this_thread::get_id();
diff --git a/Rx/v2/examples/doxygen/main.hpp b/Rx/v2/examples/doxygen/main.hpp
new file mode 100644
index 000000000..7439c6a17
--- /dev/null
+++ b/Rx/v2/examples/doxygen/main.hpp
@@ -0,0 +1,3 @@
+#pragma once
+
+std::string get_pid();
diff --git a/Rx/v2/examples/doxygen/merge.cpp b/Rx/v2/examples/doxygen/merge.cpp
index 6ff653936..008c3789c 100644
--- a/Rx/v2/examples/doxygen/merge.cpp
+++ b/Rx/v2/examples/doxygen/merge.cpp
@@ -30,7 +30,7 @@ SCENARIO("implicit merge sample"){
     printf("//! [implicit merge sample]\n");
 }
 
-std::string get_pid();
+#include "main.hpp"
 
 SCENARIO("threaded merge sample"){
     printf("//! [threaded merge sample]\n");
diff --git a/Rx/v2/examples/doxygen/merge_delay_error.cpp b/Rx/v2/examples/doxygen/merge_delay_error.cpp
index 8c28cd882..7a9457011 100644
--- a/Rx/v2/examples/doxygen/merge_delay_error.cpp
+++ b/Rx/v2/examples/doxygen/merge_delay_error.cpp
@@ -33,7 +33,7 @@ SCENARIO("implicit merge_delay_error sample"){
 	printf("//! [implicit merge_delay_error sample]\n");
 }
 
-std::string get_pid();
+#include "main.hpp"
 
 SCENARIO("threaded merge_delay_error sample"){
 	printf("//! [threaded merge_delay_error sample]\n");
diff --git a/Rx/v2/examples/doxygen/observe_on.cpp b/Rx/v2/examples/doxygen/observe_on.cpp
index 927c339c9..904699990 100644
--- a/Rx/v2/examples/doxygen/observe_on.cpp
+++ b/Rx/v2/examples/doxygen/observe_on.cpp
@@ -3,7 +3,7 @@
 #include "rxcpp/rx-test.hpp"
 #include "catch.hpp"
 
-std::string get_pid();
+#include "main.hpp"
 
 SCENARIO("observe_on sample"){
     printf("//! [observe_on sample]\n");
diff --git a/Rx/v2/examples/doxygen/pairwise.cpp b/Rx/v2/examples/doxygen/pairwise.cpp
index 3dd8d3414..3133679c6 100644
--- a/Rx/v2/examples/doxygen/pairwise.cpp
+++ b/Rx/v2/examples/doxygen/pairwise.cpp
@@ -23,7 +23,7 @@ SCENARIO("pairwise short sample"){
     printf("//! [pairwise short sample]\n");
 }
 
-//std::string get_pid();
+//#include "main.hpp"
 //
 //SCENARIO("threaded flat_map sample"){
 //    printf("//! [threaded flat_map sample]\n");
diff --git a/Rx/v2/examples/doxygen/range.cpp b/Rx/v2/examples/doxygen/range.cpp
index 69eecbd0f..3abb0ece1 100644
--- a/Rx/v2/examples/doxygen/range.cpp
+++ b/Rx/v2/examples/doxygen/range.cpp
@@ -13,7 +13,7 @@ SCENARIO("range sample"){
     printf("//! [range sample]\n");
 }
 
-std::string get_pid();
+#include "main.hpp"
 
 SCENARIO("threaded range sample"){
     printf("//! [threaded range sample]\n");
diff --git a/Rx/v2/examples/doxygen/replay.cpp b/Rx/v2/examples/doxygen/replay.cpp
index d6f08ed17..234085154 100644
--- a/Rx/v2/examples/doxygen/replay.cpp
+++ b/Rx/v2/examples/doxygen/replay.cpp
@@ -3,7 +3,7 @@
 #include "rxcpp/rx-test.hpp"
 #include "catch.hpp"
 
-std::string get_pid();
+#include "main.hpp"
 
 SCENARIO("replay sample"){
     printf("//! [replay sample]\n");
diff --git a/Rx/v2/examples/doxygen/skip_until.cpp b/Rx/v2/examples/doxygen/skip_until.cpp
index c539d8ebb..d99cb6e38 100644
--- a/Rx/v2/examples/doxygen/skip_until.cpp
+++ b/Rx/v2/examples/doxygen/skip_until.cpp
@@ -15,7 +15,7 @@ SCENARIO("skip_until sample"){
     printf("//! [skip_until sample]\n");
 }
 
-std::string get_pid();
+#include "main.hpp"
 
 SCENARIO("threaded skip_until sample"){
     printf("//! [threaded skip_until sample]\n");
diff --git a/Rx/v2/examples/doxygen/subscribe_on.cpp b/Rx/v2/examples/doxygen/subscribe_on.cpp
index e2614bc5c..7a9da50f9 100644
--- a/Rx/v2/examples/doxygen/subscribe_on.cpp
+++ b/Rx/v2/examples/doxygen/subscribe_on.cpp
@@ -3,7 +3,7 @@
 #include "rxcpp/rx-test.hpp"
 #include "catch.hpp"
 
-std::string get_pid();
+#include "main.hpp"
 
 SCENARIO("subscribe_on sample"){
     printf("//! [subscribe_on sample]\n");
diff --git a/Rx/v2/examples/doxygen/take_until.cpp b/Rx/v2/examples/doxygen/take_until.cpp
index 5c98bc41c..082171bd9 100644
--- a/Rx/v2/examples/doxygen/take_until.cpp
+++ b/Rx/v2/examples/doxygen/take_until.cpp
@@ -26,7 +26,7 @@ SCENARIO("take_until time sample"){
     printf("//! [take_until time sample]\n");
 }
 
-std::string get_pid();
+#include "main.hpp"
 
 SCENARIO("threaded take_until sample"){
     printf("//! [threaded take_until sample]\n");
diff --git a/Rx/v2/examples/doxygen/with_latest_from.cpp b/Rx/v2/examples/doxygen/with_latest_from.cpp
index 200f446bd..cf0a422fc 100644
--- a/Rx/v2/examples/doxygen/with_latest_from.cpp
+++ b/Rx/v2/examples/doxygen/with_latest_from.cpp
@@ -17,7 +17,7 @@ SCENARIO("with_latest_from sample"){
     printf("//! [with_latest_from sample]\n");
 }
 
-std::string get_pid();
+#include "main.hpp"
 
 SCENARIO("Coordination with_latest_from sample"){
     printf("//! [Coordination with_latest_from sample]\n");
diff --git a/Rx/v2/examples/doxygen/zip.cpp b/Rx/v2/examples/doxygen/zip.cpp
index c5cd07b9a..6bd295bbe 100644
--- a/Rx/v2/examples/doxygen/zip.cpp
+++ b/Rx/v2/examples/doxygen/zip.cpp
@@ -17,7 +17,7 @@ SCENARIO("zip sample"){
     printf("//! [zip sample]\n");
 }
 
-std::string get_pid();
+#include "main.hpp"
 
 SCENARIO("Coordination zip sample"){
     printf("//! [Coordination zip sample]\n");