[F] Fix incorrect behaviour in case of using standard iostream manipulators with fort::table.

ChangeLog.md

@@ -1,5 +1,9 @@
 ## v0.4.1
 
+### Bug fixes
+
+- Fix incorrect behaviour in case of using standard iostream manipulators with fort::table.
+
 ### Internal
 
 - Add alias `libfort::fort` for `fort` target that can be used via `add_subdirectory` in cmake.

lib/fort.hpp

@@ -34,9 +34,11 @@ SOFTWARE.
 #ifndef LIBFORT_HPP
 #define LIBFORT_HPP
 
+#include <iomanip>
+#include <sstream>
 #include <string>
 #include <stdexcept>
-#include <sstream>
+#include <type_traits>
 
 #include "fort.h"
 
@@ -150,6 +152,41 @@ const table_manipulator endr(1);
  */
 const table_manipulator separator(2);
 
+// Utility functions for internal library usage.
+namespace detail
+{
+template <typename T>
+constexpr bool is_stream_manipulator_impl() noexcept
+{
+    using Tdec = typename std::decay<T>::type;
+    // Manipulators for integral types
+    return std::is_same<Tdec, typename std::decay<decltype(std::dec)>::type>::value
+           || std::is_same<Tdec, typename std::decay<decltype(std::hex)>::type>::value
+           || std::is_same<Tdec, typename std::decay<decltype(std::oct)>::type>::value
+           // Floating-point manipulators
+           || std::is_same<Tdec, typename std::decay<decltype(std::fixed)>::type>::value
+           || std::is_same<Tdec, typename std::decay<decltype(std::scientific)>::type>::value
+           || std::is_same<Tdec, typename std::decay<decltype(std::hexfloat)>::type>::value
+           || std::is_same<Tdec, typename std::decay<decltype(std::defaultfloat)>::type>::value
+           // Misc
+           || std::is_same<Tdec, typename std::decay<decltype(std::setbase(0))>::type>::value
+           || std::is_same<Tdec, typename std::decay<decltype(std::setfill('\0'))>::type>::value
+           || std::is_same<Tdec, typename std::decay<decltype(std::setprecision(0))>::type>::value
+           || std::is_same<Tdec, typename std::decay<decltype(std::setw(0))>::type>::value;
+}
+}
+
+/**
+ * Utility function that is used internally by the library to check if argument
+ * passed to operator<< is a manipulator. In case default behaviour is not
+ * enough write custom specialization of this function.
+ */
+template <typename T>
+constexpr bool is_stream_manipulator() noexcept
+{
+    return detail::is_stream_manipulator_impl<T>();
+}
+
 /**
  * Property owner.
  *
@@ -534,8 +571,9 @@ public:
     template <typename T>
     table &operator<<(const T &arg)
     {
+        constexpr bool is_manip = fort::is_stream_manipulator<typename std::decay<T>::type>();
         stream_ << arg;
-        if (stream_.tellp() >= 0) {
+        if (stream_.tellp() >= 0 && !is_manip) {
 #ifdef FT_HAVE_UTF8
             if (TT == table_type::character) {
                 ft_nwrite(table_, 1, stream_.str().c_str());

src/fort.hpp

@@ -34,9 +34,11 @@ SOFTWARE.
 #ifndef LIBFORT_HPP
 #define LIBFORT_HPP
 
+#include <iomanip>
+#include <sstream>
 #include <string>
 #include <stdexcept>
-#include <sstream>
+#include <type_traits>
 
 #include "fort.h"
 
@@ -150,6 +152,41 @@ const table_manipulator endr(1);
  */
 const table_manipulator separator(2);
 
+// Utility functions for internal library usage.
+namespace detail
+{
+template <typename T>
+constexpr bool is_stream_manipulator_impl() noexcept
+{
+    using Tdec = typename std::decay<T>::type;
+    // Manipulators for integral types
+    return std::is_same<Tdec, typename std::decay<decltype(std::dec)>::type>::value
+           || std::is_same<Tdec, typename std::decay<decltype(std::hex)>::type>::value
+           || std::is_same<Tdec, typename std::decay<decltype(std::oct)>::type>::value
+           // Floating-point manipulators
+           || std::is_same<Tdec, typename std::decay<decltype(std::fixed)>::type>::value
+           || std::is_same<Tdec, typename std::decay<decltype(std::scientific)>::type>::value
+           || std::is_same<Tdec, typename std::decay<decltype(std::hexfloat)>::type>::value
+           || std::is_same<Tdec, typename std::decay<decltype(std::defaultfloat)>::type>::value
+           // Misc
+           || std::is_same<Tdec, typename std::decay<decltype(std::setbase(0))>::type>::value
+           || std::is_same<Tdec, typename std::decay<decltype(std::setfill('\0'))>::type>::value
+           || std::is_same<Tdec, typename std::decay<decltype(std::setprecision(0))>::type>::value
+           || std::is_same<Tdec, typename std::decay<decltype(std::setw(0))>::type>::value;
+}
+}
+
+/**
+ * Utility function that is used internally by the library to check if argument
+ * passed to operator<< is a manipulator. In case default behaviour is not
+ * enough write custom specialization of this function.
+ */
+template <typename T>
+constexpr bool is_stream_manipulator() noexcept
+{
+    return detail::is_stream_manipulator_impl<T>();
+}
+
 /**
  * Property owner.
  *
@@ -534,8 +571,9 @@ public:
     template <typename T>
     table &operator<<(const T &arg)
     {
+        constexpr bool is_manip = fort::is_stream_manipulator<typename std::decay<T>::type>();
         stream_ << arg;
-        if (stream_.tellp() >= 0) {
+        if (stream_.tellp() >= 0 && !is_manip) {
 #ifdef FT_HAVE_UTF8
             if (TT == table_type::character) {
                 ft_nwrite(table_, 1, stream_.str().c_str());

tests/bb_tests_cpp/test_table_basic.cpp

@@ -2,6 +2,16 @@
 #include "fort.hpp"
 #include "test_utils.hpp"
 
+namespace fort
+{
+// Write custom specialisation for testing purposes.
+using setw_type = typename std::decay<decltype(std::setw(0))>::type;
+template <>
+constexpr bool is_stream_manipulator<setw_type>() noexcept
+{
+    return false;
+}
+}
 
 void test_cpp_bug_fixes(void)
 {
@@ -97,6 +107,40 @@ void test_cpp_bug_fixes(void)
             "+------+------+--------------------------------+\n";
         assert_string_equal(table_str, table_str_etalon);
     }
+
+
+    SCENARIO("Issue 49 - https://github.com/seleznevae/libfort/issues/49") {
+        {
+            fort::char_table table;
+            table << std::setprecision(5) << 3.14 << std::hex << 256 << fort::endr
+                  << std::fixed << std::setprecision(2) << 11.1234567;
+            std::string table_str = table.to_string();
+            std::string table_str_etalon =
+                "+-------+-----+\n"
+                "|       |     |\n"
+                "|  3.14 | 100 |\n"
+                "|       |     |\n"
+                "+-------+-----+\n"
+                "|       |     |\n"
+                "| 11.12 |     |\n"
+                "|       |     |\n"
+                "+-------+-----+\n";
+            assert_string_equal(table_str, table_str_etalon);
+        }
+
+        {
+            fort::char_table table;
+            table << std::setw(15) << 3.14000001;
+            std::string table_str = table.to_string();
+            std::string table_str_etalon =
+                "+--+-----------------+\n"
+                "|  |                 |\n"
+                "|  |            3.14 |\n"
+                "|  |                 |\n"
+                "+--+-----------------+\n";
+            assert_string_equal(table_str, table_str_etalon);
+        }
+    }
 }
 
 void test_cpp_table_basic(void)