c++ - 编译 C++ 程序时出错：错误：在 '>' 标记之前预期的 unqualified-id

Question

我尝试在我的 ubuntu 18.04 上编译 C++ 程序。在程序中，我使用了一些外部库。

错误如下所示：

blib/bun/impl/orm.hpp:1995:20: error: ‘struct blib::bun::__private::type_conversion’ redeclared as different kind of symbol
             struct type_conversion<SimpleObjHolder<T>> {
                    ^~~~~~~~~~~~~~~
blib/bun/impl/orm.hpp:1944:20: note: previous declaration ‘template<class T> struct blib::bun::__private::type_conversion’
             struct type_conversion {
                    ^~~~~~~~~~~~~~~
blib/bun/impl/orm.hpp:1995:53: error: expected unqualified-id before ‘&gt;’ token
             struct type_conversion<SimpleObjHolder<T>> {
                                                     ^~
blib/bun/impl/orm.hpp:2114:12: error: ‘type_conversion’ is not a class template
     struct type_conversion<blib::bun::__private::SimpleObjHolder<T>> {
            ^~~~~~~~~~~~~~~
blib/bun/impl/orm.hpp:2114:67: error: conflicting declaration of template ‘template<class T> struct soci::type_conversion’
     struct type_conversion<blib::bun::__private::SimpleObjHolder<T>> {
                                                                   ^~
In file included from /usr/local/include/soci/exchange-traits.h:11:0,
                 from /usr/local/include/soci/into-type.h:13,
                 from /usr/local/include/soci/blob-exchange.h:12,
                 from /usr/local/include/soci/soci.h:18,
                 from /home/mike/Documents/PROJECTS/C/blib/bun/impl/DbBackend.hpp:9,
                 from blib/bun/impl/orm.hpp:41,
                 from blib/bun/bun.hpp:3,
                 from main.cpp:12:
/usr/local/include/soci/type-conversion-traits.h:19:8: note: previous declaration ‘template<class T, class Enable> struct soci::type_conversion’
 struct type_conversion
        ^~~~~~~~~~~~~~~
<builtin>: recipe for target 'main' failed
make: *** [main] Error 1

有问题的代码的示例部分如下所示：

struct type_conversion<SimpleObjHolder<T>> {
                using ObjectHolderType = SimpleObjHolder<T>;
                using ObjType = T;
......

确切的问题行是：

struct type_conversion<SimpleObjHolder<T>> {

似乎编译器无法理解语法，或者我的编译器版本不正确。

我是 C/C++ 的新手，请在这一刻澄清我..

这是生成文件：

LDFLAGS := -L/usr/local/lib -L/home/mike/Documents/PROJECTS/C/libs/socket \
-I/home/mike/Documents/PROJECTS/C/third_party/unqlite -I/home/mike/Documents/PROJECTS/C -I/home/mike/Documents/PROJECTS/C/third_party
LDLIBS :=  -lchilkat-9.5.0 -lpthread -lresolv -lsocket
EXECUTABLE := main
CXXFLAGS=-g -std=c++11 -Wall -pedantic

all: $(EXECUTABLE)

clean:
    rm -f $(EXECUTABLE) *.o

添加后报错CXXFLAGS=-g -std=c++11 -Wall -pedantic：

    blib/bun/impl/orm.hpp:1995:20: error: ‘type_conversion’ is not a class template
             struct type_conversion<SimpleObjHolder<T>> {
                    ^~~~~~~~~~~~~~~
blib/bun/impl/orm.hpp:1995:36: error: ‘SimpleObjHolder’ was not declared in this scope
             struct type_conversion<SimpleObjHolder<T>> {
                                    ^~~~~~~~~~~~~~~
blib/bun/impl/orm.hpp:1995:36: note: suggested alternative:
blib/bun/impl/orm.hpp:415:20: note:   ‘blib::bun::__private::SimpleObjHolder’
             struct SimpleObjHolder {
                    ^~~~~~~~~~~~~~~
blib/bun/impl/orm.hpp:1995:20: error: ‘struct blib::bun::__private::type_conversion’ redeclared as different kind of symbol
             struct type_conversion<SimpleObjHolder<T>> {
                    ^~~~~~~~~~~~~~~
blib/bun/impl/orm.hpp:1944:20: note: previous declaration ‘template<class T> struct blib::bun::__private::type_conversion’
             struct type_conversion {
                    ^~~~~~~~~~~~~~~
blib/bun/impl/orm.hpp:1995:53: error: expected unqualified-id before ‘&gt;’ token
             struct type_conversion<SimpleObjHolder<T>> {
                                                     ^~
blib/bun/impl/orm.hpp:2105:14: warning: extra ‘;’ [-Wpedantic]
             };
              ^
blib/bun/impl/orm.hpp:2114:12: error: ‘type_conversion’ is not a class template
     struct type_conversion<blib::bun::__private::SimpleObjHolder<T>> {
            ^~~~~~~~~~~~~~~
blib/bun/impl/orm.hpp:2114:67: error: conflicting declaration of template ‘template<class T> struct soci::type_conversion’
     struct type_conversion<blib::bun::__private::SimpleObjHolder<T>> {

我试过了CXXFLAGS=-g -std=c++11 -Wall -pedantic，，，CXXFLAGS=-g -std=c++14 -Wall -pedanticCXXFLAGS=-g -std=c++17 -Wall -pedantic

gcc 版本 7.4.0 (Ubuntu 7.4.0-1ubuntu1~18.04.1)

标签： c++