[bug#33633] [PATCH] gnu: Add a C++14 variant of Boost for packages that need it.

[Leo Famulari]

Fixes <https://bugs.gnu.org/33605> and <https://bugs.gnu.org/33610>.

* gnu/packages/boost.scm (boost-cxx14): New variable.
* gnu/packages/compression.scm (innoextract)[inputs]: Use it.
* gnu/packages/mpd.scm (ncmpcpp)[inputs]: Use it.
---
 gnu/packages/boost.scm       | 9 +++++++++
 gnu/packages/compression.scm | 2 +-
 gnu/packages/mpd.scm         | 2 +-
 3 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/gnu/packages/boost.scm b/gnu/packages/boost.scm
index b772781f5..07dce749d 100644
--- a/gnu/packages/boost.scm
+++ b/gnu/packages/boost.scm
@@ -122,6 +122,15 @@ across a broad spectrum of applications.")
     (license (license:x11-style "https://www.boost.org/LICENSE_1_0.txt";
                                 "Some components have other similar 
licences."))))
 
+(define-public boost-cxx14
+  (package (inherit boost)
+    (arguments
+      (substitute-keyword-arguments (package-arguments boost)
+        ((#:make-flags flags)
+         `(append ,flags
+                  '("cxxflags=-std=c++14")))))
+    (properties '((hidden? . #t)))))
+
 (define-public boost-for-mysql
   ;; Older version for MySQL 5.7.23.
   (package
diff --git a/gnu/packages/compression.scm b/gnu/packages/compression.scm
index 32b92a976..e8a50c676 100644
--- a/gnu/packages/compression.scm
+++ b/gnu/packages/compression.scm
@@ -2263,7 +2263,7 @@ single-member files which can't be decompressed in 
parallel.")
    (build-system cmake-build-system)
    (arguments
     `(#:tests? #f)) ;; No tests available.
-   (inputs `(("boost" ,boost)
+   (inputs `(("boost" ,boost-cxx14)
              ("libiconv" ,libiconv)
              ("xz" ,xz)))
    (native-inputs `(("pkg-config" ,pkg-config)))
diff --git a/gnu/packages/mpd.scm b/gnu/packages/mpd.scm
index fe8610ab9..0a81a3b8b 100644
--- a/gnu/packages/mpd.scm
+++ b/gnu/packages/mpd.scm
@@ -244,7 +244,7 @@ terminal using ncurses.")
                 "0m0mjb049sl62vx13h9waavysa30mk0rphacksnvf94n13la62v5"))))
     (build-system gnu-build-system)
     (inputs `(("libmpdclient" ,libmpdclient)
-              ("boost"  ,boost)
+              ("boost"  ,boost-cxx14)
               ("readline" ,readline)
               ("ncurses" ,ncurses)
               ("taglib" ,taglib)
-- 
2.19.2