examples: add a Makefile for C++ short examples

* examples/c++/Makefile: New.
* examples/c++/local.mk, examples/c++/README: Adjust.

examples/c++/Makefile

@@ -0,0 +1,21 @@
+# This Makefile is designed to be simple and readable.  It does not
+# aim at portability.  It requires GNU Make.
+
+BISON = bison
+CXX = g++
+CXXFLAGS =
+PROGS = simple variant variant-11
+
+simple: CXXFLAGS = -std=c++14
+variant-11: CXXFLAGS = -std=c++11
+
+all: $(PROGS)
+
+%.cc %.hh: %.yy
+	$(BISON) $(BISONFLAGS) -o $*.cc $<
+
+%: %.cc
+	$(CXX) $(CXXFLAGS) -o$@ $<
+
+clean:
+	rm -f $(PROGS:=.cc) $(PROGS)

examples/c++/README

@@ -2,22 +2,30 @@ This directory contains examples of Bison grammar files in C++.
 
 * Examples in C++
 
+You can run `make` to compile these examples.  And `make clean` to tidy
+afterwards.
+
 ** simple.yy - Simple example in C++14
 A very simple example in C++, based on variants and symbol constructors.
 Variants allow to use any C++ type as semantic value type, and symbol
 constructors ensure consistency between declared token type and effective
 semantic value.
 
+Run as `./simple`.
+
 Extracted from the documentation: "A Simple C++ Example".
 https://www.gnu.org/software/bison/manual/html_node/A-Simple-C_002b_002b-Example.html
 
 ** variant.yy - Self-contained example in C++98
 A varition of simple.yy, in C++98.
 
+Run as `./variant`.
+
 ** variant-11.yy - Self-contained example in modern C++
 Another variation of simple.yy, closely related to the previous one, but
 exhibiting support for C++11's move semantics.
 
+Run as `./variant` or `./variant NUMBER`.
 
 -----
 

examples/c++/local.mk

@@ -61,5 +61,5 @@ if ENABLE_CXX11
   %D%/variant-11.cc: $(BISON_IN) $(dist_pkgdata_DATA)
 endif
 
-dist_cxx_DATA = %D%/README %D%/variant.yy %D%/variant-11.yy
+dist_cxx_DATA = %D%/README %D%/Makefile %D%/variant.yy %D%/variant-11.yy
-CLEANFILES += %D%/variant.output %D%/variant-11.output
+CLEANFILES += %D%/simple.output %D%/variant.output %D%/variant-11.output