[lmi-commits] [lmi] master 0d9b36b 05/11: Make enumerators print a useful value directly

[Greg Chicares]

branch: master
commit 0d9b36b4187c5b46c2e040c9b11ecfd8267663d2
Author: Gregory W. Chicares <gchicares@sbcglobal.net>
Commit: Gregory W. Chicares <gchicares@sbcglobal.net>

    Make enumerators print a useful value directly
---
 zero.hpp | 28 ++++++++++++++++++++--------
 1 file changed, 20 insertions(+), 8 deletions(-)

diff --git a/zero.hpp b/zero.hpp
index 8b78fd4..bcc03c0 100644
--- a/zero.hpp
+++ b/zero.hpp
@@ -41,12 +41,24 @@ enum root_bias
     ,bias_higher // Require  0.0 <= f(z).
     };
 
-enum root_impetus
-    {interpolate_initialization
-    ,interpolate_bisection0
-    ,interpolate_linear
-    ,interpolate_inverse_quadratic
-    ,interpolate_bisection1 // bisection when quadratic rejected
+/// Reason for having been dispatched to a particular "activity".
+///
+/// This is deliberately defined with enum-key 'enum' rather than
+/// 'enum class' or 'enum struct'. It's the same as an 'enum class'
+/// except that its enumerators usefully decay to char for printing.
+/// Feature comparison:
+///
+///   this enum  enum class   desirable properties
+///   ---------  ----------   --------------------
+///      yes        yes       specifies underlying type
+///      yes         no       implicitly converts to char
+
+enum root_impetus : char
+    {interpolate_initialization    = 'I'
+    ,interpolate_bisection0        = 'B'
+    ,interpolate_linear            = 'L'
+    ,interpolate_inverse_quadratic = 'Q'
+    ,interpolate_bisection1        = 'b' // bisection when quadratic rejected
     };
 
 enum root_validity
@@ -285,7 +297,7 @@ root_type lmi_root
         {
         os_trace
             <<        std::setw(3)  << n_iter
-            << ' '                  << "IBLQb"[impetus]
+            << ' '                  << impetus
             << ' ' << std::setw(12) << a << ' ' << std::setw(12) << fa
             << ' ' << std::setw(12) << b << ' ' << std::setw(12) << fb
             << ' ' << std::setw(12) << c << ' ' << std::setw(12) << fc
@@ -536,7 +548,7 @@ double brent_zero
         {
         os_trace
             <<        std::setw(3)  << n_iter
-            << ' '                  << "IBLQb"[impetus]
+            << ' '                  << impetus
             << ' ' << std::setw(12) << a << ' ' << std::setw(12) << fa
             << ' ' << std::setw(12) << b << ' ' << std::setw(12) << fb
             << ' ' << std::setw(12) << c << ' ' << std::setw(12) << fc