commit 63bfaa14beef2521759571ca077834a412d12bbc
Author: Jean-Marc Lasgouttes <lasgout...@lyx.org>
Date: Tue Mar 12 12:40:32 2019 +0100
Make TextMetrics noncopyable
This is done by declaring unimplemented private copy constructor and
assignment operator.
This breaks compilation in BufferView::textMetrics, which does a copy when
inserting a TextMetrics object in the cache. Some C++11 wizardry I will not
pretend to completely understand saves the day.
See the following page for details:
https://en.cppreference.com/w/cpp/container/map/emplace
This avoids real world bugs like #11512.
---
src/BufferView.cpp | 5 +++--
src/TextMetrics.h | 3 +++
2 files changed, 6 insertions(+), 2 deletions(-)
diff --git a/src/BufferView.cpp b/src/BufferView.cpp
index 50df1aa..900207c 100644
--- a/src/BufferView.cpp
+++ b/src/BufferView.cpp
@@ -2542,8 +2542,9 @@ TextMetrics & BufferView::textMetrics(Text const * t)
LBUFERR(t);
TextMetricsCache::iterator tmc_it = d->text_metrics_.find(t);
if (tmc_it == d->text_metrics_.end()) {
- tmc_it = d->text_metrics_.insert(
- make_pair(t, TextMetrics(this, const_cast<Text
*>(t)))).first;
+ tmc_it = d->text_metrics_.emplace(std::piecewise_construct,
+ std::forward_as_tuple(t),
+ std::forward_as_tuple(this, const_cast<Text
*>(t))).first;
}
return tmc_it->second;
}
diff --git a/src/TextMetrics.h b/src/TextMetrics.h
index 26156fa..006836f 100644
--- a/src/TextMetrics.h
+++ b/src/TextMetrics.h
@@ -33,6 +33,9 @@ class Text;
/// A map from a Text to the map of paragraphs metrics
class TextMetrics
{
+ /// noncopyable
+ TextMetrics(TextMetrics const &);
+ void operator=(TextMetrics const &);
public:
/// Default constructor (only here for STL containers).
TextMetrics() : bv_(0), text_(0), max_width_(0) {}
