[glibmm/wip/dboles/ustring_format_fold_and_test] tests/glibmm_ustring_format: Test output, iomanips

[Daniel Boles <dboles src gnome org>]

commit a485da170962743f29e4a18d5d8745874042d662
Author: Daniel Boles <dboles src gnome org>
Date:   Sun Oct 14 13:33:01 2018 +0100

    tests/glibmm_ustring_format: Test output, iomanips
    
    We only tested here whether single arguments got formatted without
    throwing exceptions, but not whether they got formatted into the
    expected output or combinations of multiple types and I/O manipulators.
    
    This adds a test for that, so we at least have something to ensure that
    things are working correctly, e.g. if refactoring format() as I just did

 tests/glibmm_ustring_format/main.cc | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)
---
diff --git a/tests/glibmm_ustring_format/main.cc b/tests/glibmm_ustring_format/main.cc
index 0925f84c..76a3efab 100644
--- a/tests/glibmm_ustring_format/main.cc
+++ b/tests/glibmm_ustring_format/main.cc
@@ -1,5 +1,6 @@
 #include <glibmm.h>
 
+#include <iomanip>
 #include <iostream>
 
 int
@@ -27,5 +28,26 @@ main(int, char**)
   // This threw an exception before we added a ustring::FormatStream::stream(char*) overload.
   Glib::ustring::format(cptr);
 
+  // Test substitution of various types and I/O manipulators
+  Glib::ustring expected("The meaning of life is 42, or with 2 decimal places, 42.00.");
+  auto the = "The";
+  std::string meaning("meaning");
+  Glib::ustring life("life");
+  auto number = 42.0;
+  auto places = 2;
+  auto actual = Glib::ustring::format(the, ' ', meaning, " of ", life, " is ",
+                                      number,
+                                      ", or with ", places, " decimal places, ",
+                                      std::fixed, std::setprecision(places), number,
+                                      '.');
+
+  if (actual != expected)
+  {
+    std::cerr << "expected (" << expected.size() << "):\n" << expected << "\n\n"
+              << "actual   (" << actual  .size() << "):\n" << actual   << "\n";
+
+    return EXIT_FAILURE;
+  }
+
   return EXIT_SUCCESS;
 }