From 62a9a170097ad58ed65880365815d1fb118f5059 Mon Sep 17 00:00:00 2001
From: Simon Gene Gottlieb <simon@gottliebtfreitag.de>
Date: Tue, 11 Dec 2018 22:21:50 +0100
Subject: [PATCH] use max_digits10 instead of digits (std::numeric_limits)

This replaces all occurrences of 'std::numeric_limits<T>::digits10 + 1' with
'std::numeric_limits<T>::max_digits10'.

This will satisfy the unit test 'NodeTest.FloatingPrecisionFloat'.

Background:
Using 'std::numeric_limits<T>::digits10 + 1' is not precise enough.
Converting a 'float' into a 'string' and back to a 'float' will not always
produce the original 'float' value. To guarantee that the 'string'
representation has sufficient precision the value
'std::numeric_limits<T>::max_digits10' has to be used.
---
 include/yaml-cpp/node/convert.h | 2 +-
 src/emitterstate.cpp            | 8 ++++----
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/include/yaml-cpp/node/convert.h b/include/yaml-cpp/node/convert.h
index 45a878a..b8210c7 100644
--- a/include/yaml-cpp/node/convert.h
+++ b/include/yaml-cpp/node/convert.h
@@ -93,7 +93,7 @@ struct convert<_Null> {
   struct convert<type> {                                                 \
     static Node encode(const type& rhs) {                                \
       std::stringstream stream;                                          \
-      stream.precision(std::numeric_limits<type>::digits10 + 1);         \
+      stream.precision(std::numeric_limits<type>::max_digits10);         \
       stream << rhs;                                                     \
       return Node(stream.str());                                         \
     }                                                                    \
diff --git a/src/emitterstate.cpp b/src/emitterstate.cpp
index 3542aaf..d5f39e7 100644
--- a/src/emitterstate.cpp
+++ b/src/emitterstate.cpp
@@ -24,8 +24,8 @@ EmitterState::EmitterState()
   m_seqFmt.set(Block);
   m_mapFmt.set(Block);
   m_mapKeyFmt.set(Auto);
-  m_floatPrecision.set(std::numeric_limits<float>::digits10 + 1);
-  m_doublePrecision.set(std::numeric_limits<double>::digits10 + 1);
+  m_floatPrecision.set(std::numeric_limits<float>::max_digits10);
+  m_doublePrecision.set(std::numeric_limits<double>::max_digits10);
 }
 
 EmitterState::~EmitterState() {}
@@ -349,7 +349,7 @@ bool EmitterState::SetMapKeyFormat(EMITTER_MANIP value, FmtScope::value scope) {
 }
 
 bool EmitterState::SetFloatPrecision(std::size_t value, FmtScope::value scope) {
-  if (value > std::numeric_limits<float>::digits10 + 1)
+  if (value > std::numeric_limits<float>::max_digits10)
     return false;
   _Set(m_floatPrecision, value, scope);
   return true;
@@ -357,7 +357,7 @@ bool EmitterState::SetFloatPrecision(std::size_t value, FmtScope::value scope) {
 
 bool EmitterState::SetDoublePrecision(std::size_t value,
                                       FmtScope::value scope) {
-  if (value > std::numeric_limits<double>::digits10 + 1)
+  if (value > std::numeric_limits<double>::max_digits10)
     return false;
   _Set(m_doublePrecision, value, scope);
   return true;