[vte] sixel: More constexpr

[Christian Persch <chpe src gnome org>]

commit 74de8ced35d8ef7c3b0bdc81c90147aa00d30648
Author: Christian Persch <chpe src gnome org>
Date:   Sat Apr 3 16:07:50 2021 +0200

    sixel: More constexpr

 src/sixel-context.cc | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/src/sixel-context.cc b/src/sixel-context.cc
index b24a5b3a..20238ac6 100644
--- a/src/sixel-context.cc
+++ b/src/sixel-context.cc
@@ -444,7 +444,7 @@ Context::image_data_indexed(size_t* size,
 {
         return image_data<color_index_t>(size,
                                          (image_width() + extra_width_stride) * sizeof(color_index_t),
-                                         [](color_index_t pen) noexcept -> color_index_t { return pen; });
+                                         [](color_index_t pen) constexpr noexcept -> color_index_t { return 
pen; });
 }
 
 #ifdef VTE_COMPILATION
@@ -454,7 +454,7 @@ Context::image_data() noexcept
 {
         return reinterpret_cast<uint8_t*>(image_data<color_t>(nullptr,
                                                               
cairo_format_stride_for_width(CAIRO_FORMAT_ARGB32, image_width()),
-                                                              [&](color_index_t pen) noexcept -> color_t { 
return m_colors[pen]; }));
+                                                              [&](color_index_t pen) constexpr noexcept -> 
color_t { return m_colors[pen]; }));
 }
 
 vte::Freeable<cairo_surface_t>