lttoolbox: set required C++14 standard

textproc/lttoolbox/Portfile

@@ -7,7 +7,6 @@ version                 3.5.0
 set branch              [join [lrange [split ${version} .] 0 1] .]
 categories              textproc
 license                 GPL-2+
-platforms               darwin
 maintainers             nomaintainer
 
 description             toolbox for lexical processing, morphological analysis \
@@ -30,8 +29,11 @@ checksums               rmd160  4cb9d266657a04cd29a685d236a0b0576c7f9728 \
                         sha256  cbfc6e38ba995d80114a250f9756bd28708e9b3510bde09fe7f91e0a83bbc623 \
                         size    483444
 
-depends_build           port:pkgconfig
+depends_build           path:bin/pkg-config:pkgconfig
 
 depends_lib             port:libxml2
 
+# configure: error: Could not enable at least C++1y (C++14) - upgrade your compiler
+compiler.cxx_standard   2014
+
 livecheck.regex         /${name}-(\[0-9.\]+)${extract.suffix}